Convert string16 to base::string16 in content.

BUG=

Review URL: https://codereview.chromium.org/102593002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238447 0039d316-1c4b-4281-b951-d872f2087c98

362 files changed, 1555 insertions, 1474 deletions

diff --git a/content/browser/accessibility/accessibility_tree_formatter.cc b/content/browser/accessibility/accessibility_tree_formatter.cc
index 3e03b80..af33a42 100644
--- a/content/browser/accessibility/accessibility_tree_formatter.cc
+++ b/content/browser/accessibility/accessibility_tree_formatter.cc
@@ -55,7 +55,7 @@ AccessibilityTreeFormatter::BuildAccessibilityTree() {
 }
 
 void AccessibilityTreeFormatter::FormatAccessibilityTree(
-    string16* contents) {
+    base::string16* contents) {
   scoped_ptr<base::DictionaryValue> dict = BuildAccessibilityTree();
   RecursiveFormatAccessibilityTree(*(dict.get()), contents);
 }
@@ -76,9 +76,10 @@ void AccessibilityTreeFormatter::RecursiveBuildAccessibilityTree(
 }
 
 void AccessibilityTreeFormatter::RecursiveFormatAccessibilityTree(
-    const base::DictionaryValue& dict, string16* contents, int depth) {
-  string16 line = ToString(dict, string16(depth * kIndentSpaces, ' '));
-  if (line.find(ASCIIToUTF16(kSkipString)) != string16::npos)
+    const base::DictionaryValue& dict, base::string16* contents, int depth) {
+  base::string16 line =
+      ToString(dict, base::string16(depth * kIndentSpaces, ' '));
+  if (line.find(ASCIIToUTF16(kSkipString)) != base::string16::npos)
     return;
 
   *contents += line;
@@ -98,8 +99,9 @@ void AccessibilityTreeFormatter::AddProperties(const BrowserAccessibility& node,
   dict->SetInteger("id", node.renderer_id());
 }
 
-string16 AccessibilityTreeFormatter::ToString(const base::DictionaryValue& node,
-                                              const string16& indent) {
+base::string16 AccessibilityTreeFormatter::ToString(
+    const base::DictionaryValue& node,
+    const base::string16& indent) {
   int id_value;
   node.GetInteger("id", &id_value);
   return indent + base::IntToString16(id_value) +
@@ -142,7 +144,7 @@ void AccessibilityTreeFormatter::SetFilters(
 }
 
 bool AccessibilityTreeFormatter::MatchesFilters(
-    const string16& text, bool default_result) const {
+    const base::string16& text, bool default_result) const {
   std::vector<Filter>::const_iterator iter = filters_.begin();
   bool allow = default_result;
   for (iter = filters_.begin(); iter != filters_.end(); ++iter) {
@@ -158,7 +160,7 @@ bool AccessibilityTreeFormatter::MatchesFilters(
   return allow;
 }
 
-string16 AccessibilityTreeFormatter::FormatCoordinates(
+base::string16 AccessibilityTreeFormatter::FormatCoordinates(
     const char* name, const char* x_name, const char* y_name,
     const base::DictionaryValue& value) {
   int x, y;
@@ -170,12 +172,12 @@ string16 AccessibilityTreeFormatter::FormatCoordinates(
 }
 
 void AccessibilityTreeFormatter::WriteAttribute(
-    bool include_by_default, const std::string& attr, string16* line) {
+    bool include_by_default, const std::string& attr, base::string16* line) {
   WriteAttribute(include_by_default, UTF8ToUTF16(attr), line);
 }
 
 void AccessibilityTreeFormatter::WriteAttribute(
-    bool include_by_default, const string16& attr, string16* line) {
+    bool include_by_default, const base::string16& attr, base::string16* line) {
   if (attr.empty())
     return;
   if (!MatchesFilters(attr, include_by_default))
diff --git a/content/browser/accessibility/accessibility_tree_formatter.h b/content/browser/accessibility/accessibility_tree_formatter.h
index 006ee9a..a290886 100644
--- a/content/browser/accessibility/accessibility_tree_formatter.h
+++ b/content/browser/accessibility/accessibility_tree_formatter.h
@@ -52,7 +52,7 @@ class CONTENT_EXPORT AccessibilityTreeFormatter {
   scoped_ptr<base::DictionaryValue> BuildAccessibilityTree();
 
   // Dumps a BrowserAccessibility tree into a string.
-  void FormatAccessibilityTree(string16* contents);
+  void FormatAccessibilityTree(base::string16* contents);
 
   // A single filter specification. See GetAllowString() and GetDenyString()
   // for more information.
@@ -62,10 +62,10 @@ class CONTENT_EXPORT AccessibilityTreeFormatter {
       ALLOW_EMPTY,
       DENY
     };
-    string16 match_str;
+    base::string16 match_str;
     Type type;
 
-    Filter(string16 match_str, Type type)
+    Filter(base::string16 match_str, Type type)
         : match_str(match_str), type(type) {}
   };
 
@@ -100,12 +100,12 @@ class CONTENT_EXPORT AccessibilityTreeFormatter {
 
  protected:
   void RecursiveFormatAccessibilityTree(const BrowserAccessibility& node,
-                                        string16* contents,
+                                        base::string16* contents,
                                         int indent);
   void RecursiveBuildAccessibilityTree(const BrowserAccessibility& node,
                                        base::DictionaryValue* tree_node);
   void RecursiveFormatAccessibilityTree(const base::DictionaryValue& tree_node,
-                                        string16* contents,
+                                        base::string16* contents,
                                         int depth = 0);
 
   // Overridden by each platform to add the required attributes for each node
@@ -113,27 +113,28 @@ class CONTENT_EXPORT AccessibilityTreeFormatter {
   void AddProperties(const BrowserAccessibility& node,
                      base::DictionaryValue* dict);
 
-  string16 FormatCoordinates(const char* name,
-                             const char* x_name,
-                             const char* y_name,
-                             const base::DictionaryValue& value);
+  base::string16 FormatCoordinates(const char* name,
+                                   const char* x_name,
+                                   const char* y_name,
+                                   const base::DictionaryValue& value);
 
   // Returns a platform specific representation of a BrowserAccessibility.
   // Should be zero or more complete lines, each with |prefix| prepended
   // (to indent each line).
-  string16 ToString(const base::DictionaryValue& node, const string16& indent);
+  base::string16 ToString(const base::DictionaryValue& node,
+                          const base::string16& indent);
 
   void Initialize();
 
-  bool MatchesFilters(const string16& text, bool default_result) const;
+  bool MatchesFilters(const base::string16& text, bool default_result) const;
 
   // Writes the given attribute string out to |line| if it matches the filters.
   void WriteAttribute(bool include_by_default,
-                      const string16& attr,
-                      string16* line);
+                      const base::string16& attr,
+                      base::string16* line);
   void WriteAttribute(bool include_by_default,
                       const std::string& attr,
-                      string16* line);
+                      base::string16* line);
 
   BrowserAccessibility* root_;
 
diff --git a/content/browser/accessibility/accessibility_tree_formatter_android.cc b/content/browser/accessibility/accessibility_tree_formatter_android.cc
index ae34ef5..da5da24 100644
--- a/content/browser/accessibility/accessibility_tree_formatter_android.cc
+++ b/content/browser/accessibility/accessibility_tree_formatter_android.cc
@@ -77,11 +77,12 @@ void AccessibilityTreeFormatter::AddProperties(
   dict->SetInteger("item_count", android_node->GetItemCount());
 }
 
-string16 AccessibilityTreeFormatter::ToString(const DictionaryValue& dict,
-                                              const string16& indent) {
-  string16 line;
+base::string16 AccessibilityTreeFormatter::ToString(
+    const DictionaryValue& dict,
+    const base::string16& indent) {
+  base::string16 line;
 
-  string16 class_value;
+  base::string16 class_value;
   dict.GetString("class", &class_value);
   WriteAttribute(true, UTF16ToUTF8(class_value), &line);
 
diff --git a/content/browser/accessibility/accessibility_tree_formatter_gtk.cc b/content/browser/accessibility/accessibility_tree_formatter_gtk.cc
index 8dd6b93..0dc21ce 100644
--- a/content/browser/accessibility/accessibility_tree_formatter_gtk.cc
+++ b/content/browser/accessibility/accessibility_tree_formatter_gtk.cc
@@ -37,9 +37,10 @@ void AccessibilityTreeFormatter::AddProperties(const BrowserAccessibility& node,
   dict->SetInteger("id", node.renderer_id());
 }
 
-string16 AccessibilityTreeFormatter::ToString(const base::DictionaryValue& node,
-                                              const string16& indent) {
-  string16 line;
+base::string16 AccessibilityTreeFormatter::ToString(
+    const base::DictionaryValue& node,
+    const base::string16& indent) {
+  base::string16 line;
   std::string role_value;
   node.GetString("role", &role_value);
   if (!role_value.empty())
diff --git a/content/browser/accessibility/accessibility_tree_formatter_mac.mm b/content/browser/accessibility/accessibility_tree_formatter_mac.mm
index 58881b4..021b5fd 100644
--- a/content/browser/accessibility/accessibility_tree_formatter_mac.mm
+++ b/content/browser/accessibility/accessibility_tree_formatter_mac.mm
@@ -161,9 +161,10 @@ void AccessibilityTreeFormatter::AddProperties(const BrowserAccessibility& node,
   dict->Set(kSizeDictAttr, PopulateSize(cocoa_node).release());
 }
 
-string16 AccessibilityTreeFormatter::ToString(const base::DictionaryValue& dict,
-                                              const string16& indent) {
-  string16 line;
+base::string16 AccessibilityTreeFormatter::ToString(
+    const base::DictionaryValue& dict,
+    const base::string16& indent) {
+  base::string16 line;
   NSArray* defaultAttributes =
       [NSArray arrayWithObjects:NSAccessibilityTitleAttribute,
                                 NSAccessibilityValueAttribute,
diff --git a/content/browser/accessibility/accessibility_tree_formatter_utils_win.cc b/content/browser/accessibility/accessibility_tree_formatter_utils_win.cc
index 053e39b..e2cebc1 100644
--- a/content/browser/accessibility/accessibility_tree_formatter_utils_win.cc
+++ b/content/browser/accessibility/accessibility_tree_formatter_utils_win.cc
@@ -20,10 +20,10 @@ class AccessibilityRoleStateMap {
  public:
   static AccessibilityRoleStateMap* GetInstance();
 
-  std::map<int32, string16> ia_role_string_map;
-  std::map<int32, string16> ia2_role_string_map;
-  std::map<int32, string16> ia_state_string_map;
-  std::map<int32, string16> ia2_state_string_map;
+  std::map<int32, base::string16> ia_role_string_map;
+  std::map<int32, base::string16> ia2_role_string_map;
+  std::map<int32, base::string16> ia_state_string_map;
+  std::map<int32, base::string16> ia2_state_string_map;
 
  private:
   AccessibilityRoleStateMap();
@@ -220,44 +220,44 @@ AccessibilityRoleStateMap::AccessibilityRoleStateMap() {
 
 }  // namespace.
 
-string16 IAccessibleRoleToString(int32 ia_role) {
+base::string16 IAccessibleRoleToString(int32 ia_role) {
   return AccessibilityRoleStateMap::GetInstance()->ia_role_string_map[ia_role];
 }
 
-string16 IAccessible2RoleToString(int32 ia_role) {
+base::string16 IAccessible2RoleToString(int32 ia_role) {
   return AccessibilityRoleStateMap::GetInstance()->ia2_role_string_map[ia_role];
 }
 
 void IAccessibleStateToStringVector(int32 ia_state,
-                                    std::vector<string16>* result) {
-  const std::map<int32, string16>& state_string_map =
+                                    std::vector<base::string16>* result) {
+  const std::map<int32, base::string16>& state_string_map =
       AccessibilityRoleStateMap::GetInstance()->ia_state_string_map;
-  std::map<int32, string16>::const_iterator it;
+  std::map<int32, base::string16>::const_iterator it;
   for (it = state_string_map.begin(); it != state_string_map.end(); ++it) {
     if (it->first & ia_state)
       result->push_back(it->second);
   }
 }
 
-string16 IAccessibleStateToString(int32 ia_state) {
-  std::vector<string16> strings;
+base::string16 IAccessibleStateToString(int32 ia_state) {
+  std::vector<base::string16> strings;
   IAccessibleStateToStringVector(ia_state, &strings);
   return JoinString(strings, ',');
 }
 
 void IAccessible2StateToStringVector(int32 ia2_state,
-                                     std::vector<string16>* result) {
-  const std::map<int32, string16>& state_string_map =
+                                     std::vector<base::string16>* result) {
+  const std::map<int32, base::string16>& state_string_map =
       AccessibilityRoleStateMap::GetInstance()->ia2_state_string_map;
-  std::map<int32, string16>::const_iterator it;
+  std::map<int32, base::string16>::const_iterator it;
   for (it = state_string_map.begin(); it != state_string_map.end(); ++it) {
     if (it->first & ia2_state)
       result->push_back(it->second);
   }
 }
 
-string16 IAccessible2StateToString(int32 ia2_state) {
-  std::vector<string16> strings;
+base::string16 IAccessible2StateToString(int32 ia2_state) {
+  std::vector<base::string16> strings;
   IAccessible2StateToStringVector(ia2_state, &strings);
   return JoinString(strings, ',');
 }
diff --git a/content/browser/accessibility/accessibility_tree_formatter_utils_win.h b/content/browser/accessibility/accessibility_tree_formatter_utils_win.h
index 1baf20d..86b377a 100644
--- a/content/browser/accessibility/accessibility_tree_formatter_utils_win.h
+++ b/content/browser/accessibility/accessibility_tree_formatter_utils_win.h
@@ -13,14 +13,14 @@
 
 namespace content {
 
-CONTENT_EXPORT string16 IAccessibleRoleToString(int32 ia_role);
-CONTENT_EXPORT string16 IAccessible2RoleToString(int32 ia_role);
-CONTENT_EXPORT string16 IAccessibleStateToString(int32 ia_state);
+CONTENT_EXPORT base::string16 IAccessibleRoleToString(int32 ia_role);
+CONTENT_EXPORT base::string16 IAccessible2RoleToString(int32 ia_role);
+CONTENT_EXPORT base::string16 IAccessibleStateToString(int32 ia_state);
 CONTENT_EXPORT void IAccessibleStateToStringVector(
-    int32 ia_state, std::vector<string16>* result);
-CONTENT_EXPORT string16 IAccessible2StateToString(int32 ia2_state);
+    int32 ia_state, std::vector<base::string16>* result);
+CONTENT_EXPORT base::string16 IAccessible2StateToString(int32 ia2_state);
 CONTENT_EXPORT void IAccessible2StateToStringVector(
-  int32 ia_state, std::vector<string16>* result);
+  int32 ia_state, std::vector<base::string16>* result);
 
 }  // namespace content
 
diff --git a/content/browser/accessibility/accessibility_tree_formatter_win.cc b/content/browser/accessibility/accessibility_tree_formatter_win.cc
index 679843d..c50b526 100644
--- a/content/browser/accessibility/accessibility_tree_formatter_win.cc
+++ b/content/browser/accessibility/accessibility_tree_formatter_win.cc
@@ -76,7 +76,7 @@ void AccessibilityTreeFormatter::AddProperties(
   if (hresult == S_OK)
     dict->SetString("value", msaa_variant.m_str);
 
-  std::vector<string16> state_strings;
+  std::vector<base::string16> state_strings;
   int32 ia_state = acc_obj->ia_state();
 
   // Avoid flakiness: these states depend on whether the window is focused
@@ -87,16 +87,16 @@ void AccessibilityTreeFormatter::AddProperties(
   IAccessibleStateToStringVector(ia_state, &state_strings);
   IAccessible2StateToStringVector(acc_obj->ia2_state(), &state_strings);
   base::ListValue* states = new base::ListValue;
-  for (std::vector<string16>::const_iterator it = state_strings.begin();
+  for (std::vector<base::string16>::const_iterator it = state_strings.begin();
        it != state_strings.end();
        ++it) {
     states->AppendString(UTF16ToUTF8(*it));
   }
   dict->Set("states", states);
 
-  const std::vector<string16>& ia2_attributes = acc_obj->ia2_attributes();
+  const std::vector<base::string16>& ia2_attributes = acc_obj->ia2_attributes();
   base::ListValue* attributes = new base::ListValue;
-  for (std::vector<string16>::const_iterator it = ia2_attributes.begin();
+  for (std::vector<base::string16>::const_iterator it = ia2_attributes.begin();
        it != ia2_attributes.end();
        ++it) {
     attributes->AppendString(UTF16ToUTF8(*it));
@@ -199,15 +199,16 @@ void AccessibilityTreeFormatter::AddProperties(
   }
 }
 
-string16 AccessibilityTreeFormatter::ToString(const base::DictionaryValue& dict,
-                                              const string16& indent) {
-  string16 line;
+base::string16 AccessibilityTreeFormatter::ToString(
+    const base::DictionaryValue& dict,
+    const base::string16& indent) {
+  base::string16 line;
 
-  string16 role_value;
+  base::string16 role_value;
   dict.GetString("role", &role_value);
   WriteAttribute(true, UTF16ToUTF8(role_value), &line);
 
-  string16 name_value;
+  base::string16 name_value;
   dict.GetString("name", &name_value);
   WriteAttribute(true, base::StringPrintf(L"name='%ls'", name_value.c_str()),
                  &line);
@@ -220,7 +221,7 @@ string16 AccessibilityTreeFormatter::ToString(const base::DictionaryValue& dict,
 
     switch (value->GetType()) {
       case base::Value::TYPE_STRING: {
-        string16 string_value;
+        base::string16 string_value;
         value->GetAsString(&string_value);
         WriteAttribute(false,
                        StringPrintf(L"%ls='%ls'",
@@ -257,7 +258,7 @@ string16 AccessibilityTreeFormatter::ToString(const base::DictionaryValue& dict,
         for (base::ListValue::const_iterator it = list_value->begin();
              it != list_value->end();
              ++it) {
-          string16 string_value;
+          base::string16 string_value;
           if ((*it)->GetAsString(&string_value))
             WriteAttribute(false, string_value, &line);
         }
diff --git a/content/browser/accessibility/accessibility_ui.cc b/content/browser/accessibility/accessibility_ui.cc
index 7808cc1..5203af6 100644
--- a/content/browser/accessibility/accessibility_ui.cc
+++ b/content/browser/accessibility/accessibility_ui.cc
@@ -233,7 +233,7 @@ void AccessibilityUI::RequestAccessibilityTree(const base::ListValue* args) {
   }
   scoped_ptr<AccessibilityTreeFormatter> formatter(
       AccessibilityTreeFormatter::Create(rvh));
-  string16 accessibility_contents_utf16;
+  base::string16 accessibility_contents_utf16;
   BrowserAccessibilityManager* manager =
       host_view->GetBrowserAccessibilityManager();
   if (!manager) {
diff --git a/content/browser/accessibility/accessibility_win_browsertest.cc b/content/browser/accessibility/accessibility_win_browsertest.cc
index 8131513..bb35348 100644
--- a/content/browser/accessibility/accessibility_win_browsertest.cc
+++ b/content/browser/accessibility/accessibility_win_browsertest.cc
@@ -226,7 +226,7 @@ class AccessibleChecker {
   void CheckAccessibleValue(IAccessible* accessible);
   void CheckAccessibleState(IAccessible* accessible);
   void CheckAccessibleChildren(IAccessible* accessible);
-  string16 RoleVariantToString(const base::win::ScopedVariant& role);
+  base::string16 RoleVariantToString(const base::win::ScopedVariant& role);
 
   // Expected accessible name. Checked against IAccessible::get_accName.
   std::wstring name_;
@@ -403,13 +403,13 @@ void AccessibleChecker::CheckAccessibleChildren(IAccessible* parent) {
   }
 }
 
-string16 AccessibleChecker::RoleVariantToString(
+base::string16 AccessibleChecker::RoleVariantToString(
     const base::win::ScopedVariant& role) {
   if (role.type() == VT_I4)
     return IAccessibleRoleToString(V_I4(&role));
   if (role.type() == VT_BSTR)
-    return string16(V_BSTR(&role), SysStringLen(V_BSTR(&role)));
-  return string16();
+    return base::string16(V_BSTR(&role), SysStringLen(V_BSTR(&role)));
+  return base::string16();
 }
 
 }  // namespace
diff --git a/content/browser/accessibility/browser_accessibility.cc b/content/browser/accessibility/browser_accessibility.cc
index 45f2201..223cd8d 100644
--- a/content/browser/accessibility/browser_accessibility.cc
+++ b/content/browser/accessibility/browser_accessibility.cc
@@ -444,17 +444,17 @@ bool BrowserAccessibility::GetStringAttribute(
   return false;
 }
 
-string16 BrowserAccessibility::GetString16Attribute(
+base::string16 BrowserAccessibility::GetString16Attribute(
     StringAttribute attribute) const {
   std::string value_utf8;
   if (!GetStringAttribute(attribute, &value_utf8))
-    return string16();
+    return base::string16();
   return UTF8ToUTF16(value_utf8);
 }
 
 bool BrowserAccessibility::GetString16Attribute(
     StringAttribute attribute,
-    string16* value) const {
+    base::string16* value) const {
   std::string value_utf8;
   if (!GetStringAttribute(attribute, &value_utf8))
     return false;
@@ -522,7 +522,7 @@ bool BrowserAccessibility::GetHtmlAttribute(
 }
 
 bool BrowserAccessibility::GetHtmlAttribute(
-    const char* html_attr, string16* value) const {
+    const char* html_attr, base::string16* value) const {
   std::string value_utf8;
   if (!GetHtmlAttribute(html_attr, &value_utf8))
     return false;
@@ -537,7 +537,7 @@ bool BrowserAccessibility::GetAriaTristate(
   *is_defined = false;
   *is_mixed = false;
 
-  string16 value;
+  base::string16 value;
   if (!GetHtmlAttribute(html_attr, &value) ||
       value.empty() ||
       EqualsASCII(value, "undefined")) {
diff --git a/content/browser/accessibility/browser_accessibility.h b/content/browser/accessibility/browser_accessibility.h
index 1f858f1..701010f 100644
--- a/content/browser/accessibility/browser_accessibility.h
+++ b/content/browser/accessibility/browser_accessibility.h
@@ -192,7 +192,7 @@ class CONTENT_EXPORT BrowserAccessibility {
   // need to distinguish between the default value and a missing attribute),
   // and another that returns the default value for that type if the
   // attribute is not present. In addition, strings can be returned as
-  // either std::string or string16, for convenience.
+  // either std::string or base::string16, for convenience.
 
   bool HasBoolAttribute(AccessibilityNodeData::BoolAttribute attr) const;
   bool GetBoolAttribute(AccessibilityNodeData::BoolAttribute attr) const;
@@ -217,8 +217,8 @@ class CONTENT_EXPORT BrowserAccessibility {
                           std::string* value) const;
 
   bool GetString16Attribute(AccessibilityNodeData::StringAttribute attribute,
-                            string16* value) const;
-  string16 GetString16Attribute(
+                            base::string16* value) const;
+  base::string16 GetString16Attribute(
       AccessibilityNodeData::StringAttribute attribute) const;
 
   bool HasIntListAttribute(
@@ -234,7 +234,7 @@ class CONTENT_EXPORT BrowserAccessibility {
 
   // Retrieve the value of a html attribute from the attribute map and
   // returns true if found.
-  bool GetHtmlAttribute(const char* attr, string16* value) const;
+  bool GetHtmlAttribute(const char* attr, base::string16* value) const;
   bool GetHtmlAttribute(const char* attr, std::string* value) const;
 
   // Utility method to handle special cases for ARIA booleans, tristates and
diff --git a/content/browser/accessibility/browser_accessibility_android.cc b/content/browser/accessibility/browser_accessibility_android.cc
index 433c7a1..d5920be 100644
--- a/content/browser/accessibility/browser_accessibility_android.cc
+++ b/content/browser/accessibility/browser_accessibility_android.cc
@@ -40,7 +40,7 @@ bool BrowserAccessibilityAndroid::PlatformIsLeaf() const {
     return false;
 
   // Headings with text can drop their children.
-  string16 name = GetText();
+  base::string16 name = GetText();
   if (role() == blink::WebAXRoleHeading && !name.empty())
     return true;
 
@@ -168,15 +168,15 @@ const char* BrowserAccessibilityAndroid::GetClassName() const {
   return class_name;
 }
 
-string16 BrowserAccessibilityAndroid::GetText() const {
+base::string16 BrowserAccessibilityAndroid::GetText() const {
   if (IsIframe() ||
       role() == blink::WebAXRoleWebArea) {
-    return string16();
+    return base::string16();
   }
 
-  string16 description = GetString16Attribute(
+  base::string16 description = GetString16Attribute(
       AccessibilityNodeData::ATTR_DESCRIPTION);
-  string16 text;
+  base::string16 text;
   if (!name().empty())
     text = base::UTF8ToUTF16(name());
   else if (!description.empty())
@@ -320,7 +320,7 @@ int BrowserAccessibilityAndroid::GetTextChangeRemovedCount() const {
   return (old_len - left - right);
 }
 
-string16 BrowserAccessibilityAndroid::GetTextChangeBeforeText() const {
+base::string16 BrowserAccessibilityAndroid::GetTextChangeBeforeText() const {
   return old_value_;
 }
 
@@ -365,7 +365,7 @@ bool BrowserAccessibilityAndroid::HasOnlyStaticTextChildren() const {
 }
 
 bool BrowserAccessibilityAndroid::IsIframe() const {
-  string16 html_tag = GetString16Attribute(
+  base::string16 html_tag = GetString16Attribute(
       AccessibilityNodeData::ATTR_HTML_TAG);
   return html_tag == ASCIIToUTF16("iframe");
 }
@@ -383,7 +383,7 @@ void BrowserAccessibilityAndroid::PostInitialize() {
   if (role_ == blink::WebAXRoleAlert && first_time_)
     manager_->NotifyAccessibilityEvent(blink::WebAXEventAlert, this);
 
-  string16 live;
+  base::string16 live;
   if (GetString16Attribute(
       AccessibilityNodeData::ATTR_CONTAINER_LIVE_STATUS, &live)) {
     NotifyLiveRegionUpdate(live);
@@ -392,12 +392,13 @@ void BrowserAccessibilityAndroid::PostInitialize() {
   first_time_ = false;
 }
 
-void BrowserAccessibilityAndroid::NotifyLiveRegionUpdate(string16& aria_live) {
+void BrowserAccessibilityAndroid::NotifyLiveRegionUpdate(
+    base::string16& aria_live) {
   if (!EqualsASCII(aria_live, aria_strings::kAriaLivePolite) &&
       !EqualsASCII(aria_live, aria_strings::kAriaLiveAssertive))
     return;
 
-  string16 text = GetText();
+  base::string16 text = GetText();
   if (cached_text_ != text) {
     if (!text.empty()) {
       manager_->NotifyAccessibilityEvent(blink::WebAXEventShow,
diff --git a/content/browser/accessibility/browser_accessibility_android.h b/content/browser/accessibility/browser_accessibility_android.h
index 7cb979b..cb882f4 100644
--- a/content/browser/accessibility/browser_accessibility_android.h
+++ b/content/browser/accessibility/browser_accessibility_android.h
@@ -30,7 +30,7 @@ class BrowserAccessibilityAndroid : public BrowserAccessibility {
   bool IsVisibleToUser() const;
 
   const char* GetClassName() const;
-  string16 GetText() const;
+  base::string16 GetText() const;
 
   int GetItemIndex() const;
   int GetItemCount() const;
@@ -43,7 +43,7 @@ class BrowserAccessibilityAndroid : public BrowserAccessibility {
   int GetTextChangeFromIndex() const;
   int GetTextChangeAddedCount() const;
   int GetTextChangeRemovedCount() const;
-  string16 GetTextChangeBeforeText() const;
+  base::string16 GetTextChangeBeforeText() const;
 
   int GetSelectionStart() const;
   int GetSelectionEnd() const;
@@ -59,12 +59,12 @@ class BrowserAccessibilityAndroid : public BrowserAccessibility {
   bool HasOnlyStaticTextChildren() const;
   bool IsIframe() const;
 
-  void NotifyLiveRegionUpdate(string16& aria_live);
+  void NotifyLiveRegionUpdate(base::string16& aria_live);
 
-  string16 cached_text_;
+  base::string16 cached_text_;
   bool first_time_;
-  string16 old_value_;
-  string16 new_value_;
+  base::string16 old_value_;
+  base::string16 new_value_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityAndroid);
 };
diff --git a/content/browser/accessibility/browser_accessibility_cocoa.mm b/content/browser/accessibility/browser_accessibility_cocoa.mm
index 15ac608..9364dbb 100644
--- a/content/browser/accessibility/browser_accessibility_cocoa.mm
+++ b/content/browser/accessibility/browser_accessibility_cocoa.mm
@@ -569,7 +569,7 @@ NSDictionary* attributeToMethodNameMap = nil;
 }
 
 - (NSString*)invalid {
-  string16 invalidUTF;
+  base::string16 invalidUTF;
   if (!browserAccessibility_->GetHtmlAttribute("aria-invalid", &invalidUTF))
     return NULL;
   NSString* invalid = base::SysUTF16ToNSString(invalidUTF);
@@ -1296,10 +1296,10 @@ NSDictionary* attributeToMethodNameMap = nil;
         nil]];
   } else if ([role isEqualToString:NSAccessibilityRowRole]) {
     if (browserAccessibility_->parent()) {
-      string16 parentRole;
+      base::string16 parentRole;
       browserAccessibility_->parent()->GetHtmlAttribute(
           "role", &parentRole);
-      const string16 treegridRole(ASCIIToUTF16("treegrid"));
+      const base::string16 treegridRole(ASCIIToUTF16("treegrid"));
       if (parentRole == treegridRole) {
         [ret addObjectsFromArray:[NSArray arrayWithObjects:
             NSAccessibilityDisclosingAttribute,
diff --git a/content/browser/accessibility/browser_accessibility_state_impl_win.cc b/content/browser/accessibility/browser_accessibility_state_impl_win.cc
index 824055f..28f05e0 100644
--- a/content/browser/accessibility/browser_accessibility_state_impl_win.cc
+++ b/content/browser/accessibility/browser_accessibility_state_impl_win.cc
@@ -57,7 +57,7 @@ void BrowserAccessibilityStateImpl::UpdatePlatformSpecificHistograms() {
   for (size_t i = 0; i < module_count; i++) {
     TCHAR filename[MAX_PATH];
     GetModuleFileName(modules[i], filename, sizeof(filename));
-    string16 module_name(base::FilePath(filename).BaseName().value());
+    base::string16 module_name(base::FilePath(filename).BaseName().value());
     if (LowerCaseEqualsASCII(module_name, "fsdomsrv.dll"))
       jaws = true;
     if (LowerCaseEqualsASCII(module_name, "vbufbackend_gecko_ia2.dll"))
diff --git a/content/browser/accessibility/browser_accessibility_win.cc b/content/browser/accessibility/browser_accessibility_win.cc
index 801a2d7..fe21c82 100644
--- a/content/browser/accessibility/browser_accessibility_win.cc
+++ b/content/browser/accessibility/browser_accessibility_win.cc
@@ -58,7 +58,7 @@ class BrowserAccessibilityRelation
   CONTENT_EXPORT virtual ~BrowserAccessibilityRelation() {}
 
   CONTENT_EXPORT void Initialize(BrowserAccessibilityWin* owner,
-                                 const string16& type);
+                                 const base::string16& type);
   CONTENT_EXPORT void AddTarget(int target_id);
 
   // IAccessibleRelation methods.
@@ -75,13 +75,13 @@ class BrowserAccessibilityRelation
   }
 
  private:
-  string16 type_;
+  base::string16 type_;
   base::win::ScopedComPtr<BrowserAccessibilityWin> owner_;
   std::vector<int> target_ids_;
 };
 
 void BrowserAccessibilityRelation::Initialize(BrowserAccessibilityWin* owner,
-                                              const string16& type) {
+                                              const base::string16& type) {
   owner_ = owner;
   type_ = type;
 }
@@ -564,7 +564,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_accValue(VARIANT var_id,
   if (target->ia_role() == ROLE_SYSTEM_PROGRESSBAR ||
       target->ia_role() == ROLE_SYSTEM_SCROLLBAR ||
       target->ia_role() == ROLE_SYSTEM_SLIDER) {
-    string16 value_text = target->GetValueText();
+    base::string16 value_text = target->GetValueText();
     *value = SysAllocString(value_text.c_str());
     DCHECK(*value);
     return S_OK;
@@ -578,7 +578,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_accValue(VARIANT var_id,
         AccessibilityNodeData::ATTR_COLOR_VALUE_GREEN);
     int b = target->GetIntAttribute(
         AccessibilityNodeData::ATTR_COLOR_VALUE_BLUE);
-    string16 value_text;
+    base::string16 value_text;
     value_text = base::IntToString16((r * 100) / 255) + L"% red " +
                  base::IntToString16((g * 100) / 255) + L"% green " +
                  base::IntToString16((b * 100) / 255) + L"% blue";
@@ -684,7 +684,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_attributes(BSTR* attributes) {
 
   // The iaccessible2 attributes are a set of key-value pairs
   // separated by semicolons, with a colon between the key and the value.
-  string16 str;
+  base::string16 str;
   for (unsigned int i = 0; i < ia2_attributes_.size(); ++i) {
     if (i != 0)
       str += L';';
@@ -1133,7 +1133,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_columnDescription(long column,
     BrowserAccessibilityWin* cell = static_cast<BrowserAccessibilityWin*>(
         manager_->GetFromRendererID(cell_id));
     if (cell && cell->role_ == blink::WebAXRoleColumnHeader) {
-      string16 cell_name = cell->GetString16Attribute(
+      base::string16 cell_name = cell->GetString16Attribute(
           AccessibilityNodeData::ATTR_NAME);
       if (cell_name.size() > 0) {
         *description = SysAllocString(cell_name.c_str());
@@ -1320,7 +1320,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_rowDescription(long row,
     BrowserAccessibilityWin* cell =
         manager_->GetFromRendererID(cell_id)->ToBrowserAccessibilityWin();
     if (cell && cell->role_ == blink::WebAXRoleRowHeader) {
-      string16 cell_name = cell->GetString16Attribute(
+      base::string16 cell_name = cell->GetString16Attribute(
           AccessibilityNodeData::ATTR_NAME);
       if (cell_name.size() > 0) {
         *description = SysAllocString(cell_name.c_str());
@@ -1926,7 +1926,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_characterExtents(
   if (!out_x || !out_y || !out_width || !out_height)
     return E_INVALIDARG;
 
-  const string16& text_str = TextForIAccessibleText();
+  const base::string16& text_str = TextForIAccessibleText();
   HandleSpecialTextOffset(text_str, &offset);
 
   if (offset < 0 || offset > static_cast<LONG>(text_str.size()))
@@ -2010,7 +2010,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_text(LONG start_offset,
   if (!text)
     return E_INVALIDARG;
 
-  const string16& text_str = TextForIAccessibleText();
+  const base::string16& text_str = TextForIAccessibleText();
 
   // Handle special text offsets.
   HandleSpecialTextOffset(text_str, &start_offset);
@@ -2031,7 +2031,8 @@ STDMETHODIMP BrowserAccessibilityWin::get_text(LONG start_offset,
   if (end_offset > len)
     return E_INVALIDARG;
 
-  string16 substr = text_str.substr(start_offset, end_offset - start_offset);
+  base::string16 substr = text_str.substr(start_offset,
+                                          end_offset - start_offset);
   if (substr.empty())
     return S_FALSE;
 
@@ -2061,7 +2062,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_textAtOffset(
     return S_FALSE;
   }
 
-  const string16& text_str = TextForIAccessibleText();
+  const base::string16& text_str = TextForIAccessibleText();
 
   *start_offset = FindBoundary(
       text_str, boundary_type, offset, ui::BACKWARDS_DIRECTION);
@@ -2091,7 +2092,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_textBeforeOffset(
     return S_FALSE;
   }
 
-  const string16& text_str = TextForIAccessibleText();
+  const base::string16& text_str = TextForIAccessibleText();
 
   *start_offset = FindBoundary(
       text_str, boundary_type, offset, ui::BACKWARDS_DIRECTION);
@@ -2120,7 +2121,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_textAfterOffset(
     return S_FALSE;
   }
 
-  const string16& text_str = TextForIAccessibleText();
+  const base::string16& text_str = TextForIAccessibleText();
 
   *start_offset = offset;
   *end_offset = FindBoundary(
@@ -2135,7 +2136,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_newText(IA2TextSegment* new_text) {
   if (!new_text)
     return E_INVALIDARG;
 
-  string16 text = TextForIAccessibleText();
+  base::string16 text = TextForIAccessibleText();
 
   new_text->text = SysAllocString(text.c_str());
   new_text->start = 0;
@@ -2196,7 +2197,7 @@ STDMETHODIMP BrowserAccessibilityWin::addSelection(LONG start_offset,
   if (!instance_active_)
     return E_FAIL;
 
-  const string16& text_str = TextForIAccessibleText();
+  const base::string16& text_str = TextForIAccessibleText();
   HandleSpecialTextOffset(text_str, &start_offset);
   HandleSpecialTextOffset(text_str, &end_offset);
 
@@ -2219,7 +2220,7 @@ STDMETHODIMP BrowserAccessibilityWin::setCaretOffset(LONG offset) {
   if (!instance_active_)
     return E_FAIL;
 
-  const string16& text_str = TextForIAccessibleText();
+  const base::string16& text_str = TextForIAccessibleText();
   HandleSpecialTextOffset(text_str, &offset);
   manager_->SetTextSelection(*this, offset, offset);
   return S_OK;
@@ -2234,7 +2235,7 @@ STDMETHODIMP BrowserAccessibilityWin::setSelection(LONG selection_index,
   if (selection_index != 0)
     return E_INVALIDARG;
 
-  const string16& text_str = TextForIAccessibleText();
+  const base::string16& text_str = TextForIAccessibleText();
   HandleSpecialTextOffset(text_str, &start_offset);
   HandleSpecialTextOffset(text_str, &end_offset);
 
@@ -2429,7 +2430,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_nodeInfo(
     return E_INVALIDARG;
   }
 
-  string16 tag;
+  base::string16 tag;
   if (GetString16Attribute(AccessibilityNodeData::ATTR_HTML_TAG, &tag))
     *node_name = SysAllocString(tag.c_str());
   else
@@ -2522,7 +2523,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_computedStyle(
 
   // We only cache a single style property for now: DISPLAY
 
-  string16 display;
+  base::string16 display;
   if (max_style_properties == 0 ||
       !GetString16Attribute(AccessibilityNodeData::ATTR_DISPLAY, &display)) {
     *num_style_properties = 0;
@@ -2550,10 +2551,10 @@ STDMETHODIMP BrowserAccessibilityWin::get_computedStyleForProperties(
   // We only cache a single style property for now: DISPLAY
 
   for (unsigned short i = 0; i < num_style_properties; ++i) {
-    string16 name = (LPCWSTR)style_properties[i];
+    base::string16 name = (LPCWSTR)style_properties[i];
     StringToLowerASCII(&name);
     if (name == L"display") {
-      string16 display = GetString16Attribute(
+      base::string16 display = GetString16Attribute(
           AccessibilityNodeData::ATTR_DISPLAY);
       style_values[i] = SysAllocString(display.c_str());
     } else {
@@ -2713,7 +2714,7 @@ STDMETHODIMP BrowserAccessibilityWin::get_unclippedSubstringBounds(
   if (!out_x || !out_y || !out_width || !out_height)
     return E_INVALIDARG;
 
-  const string16& text_str = TextForIAccessibleText();
+  const base::string16& text_str = TextForIAccessibleText();
   if (start_index > text_str.size() ||
       end_index > text_str.size() ||
       start_index > end_index) {
@@ -2738,7 +2739,7 @@ STDMETHODIMP BrowserAccessibilityWin::scrollToSubstring(
   if (!instance_active_)
     return E_FAIL;
 
-  const string16& text_str = TextForIAccessibleText();
+  const base::string16& text_str = TextForIAccessibleText();
   if (start_index > text_str.size() ||
       end_index > text_str.size() ||
       start_index > end_index) {
@@ -2958,7 +2959,7 @@ void BrowserAccessibilityWin::PreInitialize() {
       for (size_t i = 0; i < unique_cell_ids.size(); ++i) {
         if (unique_cell_ids[i] == renderer_id_) {
           ia2_attributes_.push_back(
-              string16(L"table-cell-index:") + base::IntToString16(i));
+              base::string16(L"table-cell-index:") + base::IntToString16(i));
         }
       }
     }
@@ -3097,7 +3098,7 @@ void BrowserAccessibilityWin::PostInitialize() {
     manager_->NotifyAccessibilityEvent(blink::WebAXEventAlert, this);
 
   // Fire events if text has changed.
-  string16 text = TextForIAccessibleText();
+  base::string16 text = TextForIAccessibleText();
   if (previous_text_ != text) {
     if (!previous_text_.empty() && !text.empty()) {
       manager_->NotifyAccessibilityEvent(
@@ -3185,7 +3186,7 @@ BrowserAccessibilityWin* BrowserAccessibilityWin::GetTargetFromChildID(
 HRESULT BrowserAccessibilityWin::GetStringAttributeAsBstr(
     AccessibilityNodeData::StringAttribute attribute,
     BSTR* value_bstr) {
-  string16 str;
+  base::string16 str;
 
   if (!GetString16Attribute(attribute, &str))
     return S_FALSE;
@@ -3202,7 +3203,7 @@ HRESULT BrowserAccessibilityWin::GetStringAttributeAsBstr(
 void BrowserAccessibilityWin::StringAttributeToIA2(
     AccessibilityNodeData::StringAttribute attribute,
     const char* ia2_attr) {
-  string16 value;
+  base::string16 value;
   if (GetString16Attribute(attribute, &value))
     ia2_attributes_.push_back(ASCIIToUTF16(ia2_attr) + L":" + value);
 }
@@ -3227,9 +3228,9 @@ void BrowserAccessibilityWin::IntAttributeToIA2(
   }
 }
 
-string16 BrowserAccessibilityWin::GetValueText() {
+base::string16 BrowserAccessibilityWin::GetValueText() {
   float fval;
-  string16 value = UTF8ToUTF16(value_);
+  base::string16 value = UTF8ToUTF16(value_);
   if (value.empty() &&
       GetFloatAttribute(AccessibilityNodeData::ATTR_VALUE_FOR_RANGE, &fval)) {
     value = UTF8ToUTF16(base::DoubleToString(fval));
@@ -3237,15 +3238,16 @@ string16 BrowserAccessibilityWin::GetValueText() {
   return value;
 }
 
-string16 BrowserAccessibilityWin::TextForIAccessibleText() {
+base::string16 BrowserAccessibilityWin::TextForIAccessibleText() {
   if (IsEditableText())
     return UTF8ToUTF16(value_);
   return (role_ == blink::WebAXRoleStaticText) ?
       UTF8ToUTF16(name_) : hypertext_;
 }
 
-void BrowserAccessibilityWin::HandleSpecialTextOffset(const string16& text,
-                                                      LONG* offset) {
+void BrowserAccessibilityWin::HandleSpecialTextOffset(
+    const base::string16& text,
+    LONG* offset) {
   if (*offset == IA2_TEXT_OFFSET_LENGTH)
     *offset = static_cast<LONG>(text.size());
   else if (*offset == IA2_TEXT_OFFSET_CARET)
@@ -3268,7 +3270,7 @@ ui::TextBoundaryType BrowserAccessibilityWin::IA2TextBoundaryToTextBoundary(
 }
 
 LONG BrowserAccessibilityWin::FindBoundary(
-    const string16& text,
+    const base::string16& text,
     IA2TextBoundaryType ia2_boundary,
     LONG start_offset,
     ui::TextBoundaryDirection direction) {
@@ -3345,7 +3347,7 @@ void BrowserAccessibilityWin::InitRoleAndState() {
   if (!HasState(blink::WebAXStateReadonly))
     ia2_state_ |= IA2_STATE_EDITABLE;
 
-  string16 invalid;
+  base::string16 invalid;
   if (GetHtmlAttribute("aria-invalid", &invalid))
     ia2_state_ |= IA2_STATE_INVALID_ENTRY;
 
@@ -3355,7 +3357,7 @@ void BrowserAccessibilityWin::InitRoleAndState() {
   if (GetBoolAttribute(AccessibilityNodeData::ATTR_CAN_SET_VALUE))
     ia2_state_ |= IA2_STATE_EDITABLE;
 
-  string16 html_tag = GetString16Attribute(
+  base::string16 html_tag = GetString16Attribute(
       AccessibilityNodeData::ATTR_HTML_TAG);
   ia_role_ = 0;
   ia2_role_ = 0;
@@ -3469,7 +3471,7 @@ void BrowserAccessibilityWin::InitRoleAndState() {
       ia_state_ |= STATE_SYSTEM_READONLY;
       break;
     case blink::WebAXRoleGroup: {
-      string16 aria_role = GetString16Attribute(
+      base::string16 aria_role = GetString16Attribute(
           AccessibilityNodeData::ATTR_ROLE);
       if (aria_role == L"group" || html_tag == L"fieldset") {
         ia_role_ = ROLE_SYSTEM_GROUPING;
@@ -3667,7 +3669,7 @@ void BrowserAccessibilityWin::InitRoleAndState() {
       ia_role_ = ROLE_SYSTEM_PAGETAB;
       break;
     case blink::WebAXRoleTable: {
-      string16 aria_role = GetString16Attribute(
+      base::string16 aria_role = GetString16Attribute(
           AccessibilityNodeData::ATTR_ROLE);
       if (aria_role == L"treegrid") {
         ia_role_ = ROLE_SYSTEM_OUTLINE;
diff --git a/content/browser/accessibility/browser_accessibility_win.h b/content/browser/accessibility/browser_accessibility_win.h
index 1bb6ee2..992b3d1 100644
--- a/content/browser/accessibility/browser_accessibility_win.h
+++ b/content/browser/accessibility/browser_accessibility_win.h
@@ -86,8 +86,8 @@ BrowserAccessibilityWin
 
   // Mappings from roles and states to human readable strings. Initialize
   // with |InitializeStringMaps|.
-  static std::map<int32, string16> role_string_map;
-  static std::map<int32, string16> state_string_map;
+  static std::map<int32, base::string16> role_string_map;
+  static std::map<int32, base::string16> state_string_map;
 
   CONTENT_EXPORT BrowserAccessibilityWin();
 
@@ -765,10 +765,10 @@ BrowserAccessibilityWin
   // Accessors.
   int32 ia_role() const { return ia_role_; }
   int32 ia_state() const { return ia_state_; }
-  const string16& role_name() const { return role_name_; }
+  const base::string16& role_name() const { return role_name_; }
   int32 ia2_role() const { return ia2_role_; }
   int32 ia2_state() const { return ia2_state_; }
-  const std::vector<string16>& ia2_attributes() const {
+  const std::vector<base::string16>& ia2_attributes() const {
     return ia2_attributes_;
   }
 
@@ -813,15 +813,15 @@ BrowserAccessibilityWin
 
   // Get the value text, which might come from the floating-point
   // value for some roles.
-  string16 GetValueText();
+  base::string16 GetValueText();
 
   // Get the text of this node for the purposes of IAccessibleText - it may
   // be the name, it may be the value, etc. depending on the role.
-  string16 TextForIAccessibleText();
+  base::string16 TextForIAccessibleText();
 
   // If offset is a member of IA2TextSpecialOffsets this function updates the
   // value of offset and returns, otherwise offset remains unchanged.
-  void HandleSpecialTextOffset(const string16& text, LONG* offset);
+  void HandleSpecialTextOffset(const base::string16& text, LONG* offset);
 
   // Convert from a IA2TextBoundaryType to a ui::TextBoundaryType.
   ui::TextBoundaryType IA2TextBoundaryToTextBoundary(IA2TextBoundaryType type);
@@ -829,7 +829,7 @@ BrowserAccessibilityWin
   // Search forwards (direction == 1) or backwards (direction == -1)
   // from the given offset until the given boundary is found, and
   // return the offset of that boundary.
-  LONG FindBoundary(const string16& text,
+  LONG FindBoundary(const base::string16& text,
                     IA2TextBoundaryType ia2_boundary,
                     LONG start_offset,
                     ui::TextBoundaryDirection direction);
@@ -846,26 +846,26 @@ BrowserAccessibilityWin
   // IAccessible role and state.
   int32 ia_role_;
   int32 ia_state_;
-  string16 role_name_;
+  base::string16 role_name_;
 
   // IAccessible2 role and state.
   int32 ia2_role_;
   int32 ia2_state_;
 
   // IAccessible2 attributes.
-  std::vector<string16> ia2_attributes_;
+  std::vector<base::string16> ia2_attributes_;
 
   // True in Initialize when the object is first created, and false
   // subsequent times.
   bool first_time_;
 
   // The previous text, before the last update to this object.
-  string16 previous_text_;
+  base::string16 previous_text_;
 
   // The old text to return in IAccessibleText::get_oldText - this is like
   // previous_text_ except that it's NOT updated when the object
   // is initialized again but the text doesn't change.
-  string16 old_text_;
+  base::string16 old_text_;
 
   // The previous state, used to see if there was a state change.
   int32 old_ia_state_;
@@ -874,7 +874,7 @@ BrowserAccessibilityWin
   std::vector<BrowserAccessibilityRelation*> relations_;
 
   // The text of this node including embedded hyperlink characters.
-  string16 hypertext_;
+  base::string16 hypertext_;
 
   // Maps the |hypertext_| embedded character offset to an index in
   // |hyperlinks_|.
diff --git a/content/browser/accessibility/browser_accessibility_win_unittest.cc b/content/browser/accessibility/browser_accessibility_win_unittest.cc
index edb572f..c1159e6 100644
--- a/content/browser/accessibility/browser_accessibility_win_unittest.cc
+++ b/content/browser/accessibility/browser_accessibility_win_unittest.cc
@@ -219,7 +219,7 @@ TEST_F(BrowserAccessibilityTest, TestChildrenChange) {
   base::win::ScopedBstr name;
   hr = text_accessible->get_accName(childid_self, name.Receive());
   ASSERT_EQ(S_OK, hr);
-  EXPECT_EQ(L"old text", string16(name));
+  EXPECT_EQ(L"old text", base::string16(name));
   name.Reset();
 
   text_dispatch.Release();
@@ -250,7 +250,7 @@ TEST_F(BrowserAccessibilityTest, TestChildrenChange) {
 
   hr = text_accessible->get_accName(childid_self, name.Receive());
   ASSERT_EQ(S_OK, hr);
-  EXPECT_EQ(L"new text", string16(name));
+  EXPECT_EQ(L"new text", base::string16(name));
 
   text_dispatch.Release();
   text_accessible.Release();
@@ -354,7 +354,7 @@ TEST_F(BrowserAccessibilityTest, TestTextBoundaries) {
 
   base::win::ScopedBstr text;
   ASSERT_EQ(S_OK, text1_obj->get_text(0, text1_len, text.Receive()));
-  ASSERT_EQ(text1_value, base::UTF16ToUTF8(string16(text)));
+  ASSERT_EQ(text1_value, base::UTF16ToUTF8(base::string16(text)));
   text.Reset();
 
   ASSERT_EQ(S_OK, text1_obj->get_text(0, 4, text.Receive()));
@@ -452,7 +452,7 @@ TEST_F(BrowserAccessibilityTest, TestSimpleHypertext) {
 
   base::win::ScopedBstr text;
   ASSERT_EQ(S_OK, root_obj->get_text(0, text_len, text.Receive()));
-  EXPECT_EQ(text1_name + text2_name, base::UTF16ToUTF8(string16(text)));
+  EXPECT_EQ(text1_name + text2_name, base::UTF16ToUTF8(base::string16(text)));
 
   long hyperlink_count;
   ASSERT_EQ(S_OK, root_obj->get_nHyperlinks(&hyperlink_count));
@@ -548,7 +548,7 @@ TEST_F(BrowserAccessibilityTest, TestComplexHypertext) {
   const std::string embed = base::UTF16ToUTF8(
       BrowserAccessibilityWin::kEmbeddedCharacter);
   EXPECT_EQ(text1_name + embed + text2_name + embed,
-            UTF16ToUTF8(string16(text)));
+            UTF16ToUTF8(base::string16(text)));
   text.Reset();
 
   long hyperlink_count;
@@ -566,7 +566,7 @@ TEST_F(BrowserAccessibilityTest, TestComplexHypertext) {
             hyperlink.QueryInterface<IAccessibleText>(hypertext.Receive()));
   EXPECT_EQ(S_OK, hypertext->get_text(0, 3, text.Receive()));
   EXPECT_STREQ(button1_text_name.c_str(),
-               base::UTF16ToUTF8(string16(text)).c_str());
+               base::UTF16ToUTF8(base::string16(text)).c_str());
   text.Reset();
   hyperlink.Release();
   hypertext.Release();
@@ -576,7 +576,7 @@ TEST_F(BrowserAccessibilityTest, TestComplexHypertext) {
             hyperlink.QueryInterface<IAccessibleText>(hypertext.Receive()));
   EXPECT_EQ(S_OK, hypertext->get_text(0, 4, text.Receive()));
   EXPECT_STREQ(link1_text_name.c_str(),
-               base::UTF16ToUTF8(string16(text)).c_str());
+               base::UTF16ToUTF8(base::string16(text)).c_str());
   text.Reset();
   hyperlink.Release();
   hypertext.Release();
diff --git a/content/browser/accessibility/dump_accessibility_tree_browsertest.cc b/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
index 45bf951..3dd07d8 100644
--- a/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
+++ b/content/browser/accessibility/dump_accessibility_tree_browsertest.cc
@@ -169,7 +169,7 @@ void DumpAccessibilityTreeTest::RunTest(
   }
 
   // Load the page.
-  string16 html_contents16;
+  base::string16 html_contents16;
   html_contents16 = UTF8ToUTF16(html_contents);
   GURL url = GetTestUrl("accessibility",
                         html_file.BaseName().MaybeAsASCII().c_str());
@@ -191,7 +191,7 @@ void DumpAccessibilityTreeTest::RunTest(
   formatter.SetFilters(filters);
 
   // Perform a diff (or write the initial baseline).
-  string16 actual_contents_utf16;
+  base::string16 actual_contents_utf16;
   formatter.FormatAccessibilityTree(&actual_contents_utf16);
   std::string actual_contents = UTF16ToUTF8(actual_contents_utf16);
   std::vector<std::string> actual_lines, expected_lines;
diff --git a/content/browser/android/content_view_core_impl.cc b/content/browser/android/content_view_core_impl.cc
index 2a53563..0f61633 100644
--- a/content/browser/android/content_view_core_impl.cc
+++ b/content/browser/android/content_view_core_impl.cc
@@ -389,7 +389,7 @@ void ContentViewCoreImpl::UpdateFrameInfo(
       overdraw_bottom_height);
 }
 
-void ContentViewCoreImpl::SetTitle(const string16& title) {
+void ContentViewCoreImpl::SetTitle(const base::string16& title) {
   JNIEnv* env = AttachCurrentThread();
   ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
   if (obj.is_null())
@@ -438,7 +438,7 @@ void ContentViewCoreImpl::ShowSelectPopupMenu(
 
   ScopedJavaLocalRef<jintArray> enabled_array(env,
                                               env->NewIntArray(items.size()));
-  std::vector<string16> labels;
+  std::vector<base::string16> labels;
   labels.reserve(items.size());
   for (size_t i = 0; i < items.size(); ++i) {
     labels.push_back(items[i].label);
@@ -1487,7 +1487,7 @@ void ContentViewCoreImpl::EvaluateJavaScript(JNIEnv* env,
 
   if (!callback) {
     // No callback requested.
-    rvh->ExecuteJavascriptInWebFrame(string16(),  // frame_xpath
+    rvh->ExecuteJavascriptInWebFrame(base::string16(),  // frame_xpath
                                      ConvertJavaStringToUTF16(env, script));
     return;
   }
@@ -1500,7 +1500,7 @@ void ContentViewCoreImpl::EvaluateJavaScript(JNIEnv* env,
       base::Bind(&JavaScriptResultCallback, j_callback);
 
   rvh->ExecuteJavascriptInWebFrameCallbackResult(
-      string16(),  // frame_xpath
+      base::string16(),  // frame_xpath
       ConvertJavaStringToUTF16(env, script),
       c_callback);
 }
diff --git a/content/browser/android/content_view_core_impl.h b/content/browser/android/content_view_core_impl.h
index 0c3a5ec..138aecc 100644
--- a/content/browser/android/content_view_core_impl.h
+++ b/content/browser/android/content_view_core_impl.h
@@ -258,7 +258,7 @@ class ContentViewCoreImpl : public ContentViewCore,
                         int selection_start, int selection_end,
                         int composition_start, int composition_end,
                         bool show_ime_if_needed, bool require_ack);
-  void SetTitle(const string16& title);
+  void SetTitle(const base::string16& title);
   void OnBackgroundColorChanged(SkColor color);
 
   bool HasFocus();
diff --git a/content/browser/android/content_view_statics.cc b/content/browser/android/content_view_statics.cc
index 917da58..e176564 100644
--- a/content/browser/android/content_view_statics.cc
+++ b/content/browser/android/content_view_statics.cc
@@ -62,8 +62,8 @@ void ResumeWebkitSharedTimers(const std::vector<int>& suspended_processes) {
 
 // Returns the first substring consisting of the address of a physical location.
 static jstring FindAddress(JNIEnv* env, jclass clazz, jstring addr) {
-  string16 content_16 = ConvertJavaStringToUTF16(env, addr);
-  string16 result_16;
+  base::string16 content_16 = ConvertJavaStringToUTF16(env, addr);
+  base::string16 result_16;
   if (content::address_parser::FindAddress(content_16, &result_16))
     return ConvertUTF16ToJavaString(env, result_16).Release();
   return NULL;
diff --git a/content/browser/android/web_contents_observer_android.cc b/content/browser/android/web_contents_observer_android.cc
index f2494e8..235041b 100644
--- a/content/browser/android/web_contents_observer_android.cc
+++ b/content/browser/android/web_contents_observer_android.cc
@@ -98,11 +98,11 @@ void WebContentsObserverAndroid::DidStopLoading(
 
 void WebContentsObserverAndroid::DidFailProvisionalLoad(
     int64 frame_id,
-    const string16& frame_unique_name,
+    const base::string16& frame_unique_name,
     bool is_main_frame,
     const GURL& validated_url,
     int error_code,
-    const string16& error_description,
+    const base::string16& error_description,
     RenderViewHost* render_view_host) {
   DidFailLoadInternal(
         true, is_main_frame, error_code, error_description, validated_url);
@@ -113,7 +113,7 @@ void WebContentsObserverAndroid::DidFailLoad(
     const GURL& validated_url,
     bool is_main_frame,
     int error_code,
-    const string16& error_description,
+    const base::string16& error_description,
     RenderViewHost* render_view_host) {
   DidFailLoadInternal(
         false, is_main_frame, error_code, error_description, validated_url);
@@ -175,7 +175,7 @@ void WebContentsObserverAndroid::DidStartProvisionalLoadForFrame(
 
 void WebContentsObserverAndroid::DidCommitProvisionalLoadForFrame(
       int64 frame_id,
-      const string16& frame_unique_name,
+      const base::string16& frame_unique_name,
       bool is_main_frame,
       const GURL& url,
       PageTransition transition_type,
@@ -251,7 +251,7 @@ void WebContentsObserverAndroid::DidFailLoadInternal(
     bool is_provisional_load,
     bool is_main_frame,
     int error_code,
-    const string16& description,
+    const base::string16& description,
     const GURL& url) {
   JNIEnv* env = AttachCurrentThread();
   ScopedJavaLocalRef<jobject> obj(weak_java_observer_.get(env));
diff --git a/content/browser/android/web_contents_observer_android.h b/content/browser/android/web_contents_observer_android.h
index 9742d28..15a1363 100644
--- a/content/browser/android/web_contents_observer_android.h
+++ b/content/browser/android/web_contents_observer_android.h
@@ -38,17 +38,17 @@ class WebContentsObserverAndroid : public WebContentsObserver {
   virtual void DidStopLoading(RenderViewHost* render_view_host) OVERRIDE;
   virtual void DidFailProvisionalLoad(
       int64 frame_id,
-      const string16& frame_unique_name,
+      const base::string16& frame_unique_name,
       bool is_main_frame,
       const GURL& validated_url,
       int error_code,
-      const string16& error_description,
+      const base::string16& error_description,
       RenderViewHost* render_view_host) OVERRIDE;
   virtual void DidFailLoad(int64 frame_id,
                            const GURL& validated_url,
                            bool is_main_frame,
                            int error_code,
-                           const string16& error_description,
+                           const base::string16& error_description,
                            RenderViewHost* render_view_host) OVERRIDE;
   virtual void DidNavigateMainFrame(const LoadCommittedDetails& details,
                                     const FrameNavigateParams& params) OVERRIDE;
@@ -64,7 +64,7 @@ class WebContentsObserverAndroid : public WebContentsObserver {
       RenderViewHost* render_view_host) OVERRIDE;
   virtual void DidCommitProvisionalLoadForFrame(
       int64 frame_id,
-      const string16& frame_unique_name,
+      const base::string16& frame_unique_name,
       bool is_main_frame,
       const GURL& url,
       PageTransition transition_type,
@@ -83,7 +83,7 @@ class WebContentsObserverAndroid : public WebContentsObserver {
   void DidFailLoadInternal(bool is_provisional_load,
                            bool is_main_frame,
                            int error_code,
-                           const string16& description,
+                           const base::string16& description,
                            const GURL& url);
 
   JavaObjectWeakGlobalRef weak_java_observer_;
diff --git a/content/browser/browser_child_process_host_impl.cc b/content/browser/browser_child_process_host_impl.cc
index 8e6bde3..4261572 100644
--- a/content/browser/browser_child_process_host_impl.cc
+++ b/content/browser/browser_child_process_host_impl.cc
@@ -192,7 +192,7 @@ base::ProcessHandle BrowserChildProcessHostImpl::GetHandle() const {
   return child_process_->GetHandle();
 }
 
-void BrowserChildProcessHostImpl::SetName(const string16& name) {
+void BrowserChildProcessHostImpl::SetName(const base::string16& name) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   data_.name = name;
 }
diff --git a/content/browser/browser_child_process_host_impl.h b/content/browser/browser_child_process_host_impl.h
index 6345595..428da3d 100644
--- a/content/browser/browser_child_process_host_impl.h
+++ b/content/browser/browser_child_process_host_impl.h
@@ -54,7 +54,7 @@ class CONTENT_EXPORT BrowserChildProcessHostImpl
   virtual ChildProcessHost* GetHost() const OVERRIDE;
   virtual base::TerminationStatus GetTerminationStatus(
       bool known_dead, int* exit_code) OVERRIDE;
-  virtual void SetName(const string16& name) OVERRIDE;
+  virtual void SetName(const base::string16& name) OVERRIDE;
   virtual void SetHandle(base::ProcessHandle handle) OVERRIDE;
 
   // Returns the handle of the child process. This can be called only after
diff --git a/content/browser/browser_plugin/browser_plugin_guest.cc b/content/browser/browser_plugin/browser_plugin_guest.cc
index 7d166a6..6d28a5e 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.cc
+++ b/content/browser/browser_plugin/browser_plugin_guest.cc
@@ -365,9 +365,9 @@ BrowserPluginGuest::BrowserPluginGuest(
 
 bool BrowserPluginGuest::AddMessageToConsole(WebContents* source,
                                              int32 level,
-                                             const string16& message,
+                                             const base::string16& message,
                                              int32 line_no,
-                                             const string16& source_id) {
+                                             const base::string16& source_id) {
   if (!delegate_)
     return false;
 
@@ -796,7 +796,7 @@ WebContents* BrowserPluginGuest::OpenURLFromTab(WebContents* source,
 
 void BrowserPluginGuest::WebContentsCreated(WebContents* source_contents,
                                             int64 source_frame_id,
-                                            const string16& frame_name,
+                                            const base::string16& frame_name,
                                             const GURL& target_url,
                                             WebContents* new_contents) {
   WebContentsImpl* new_contents_impl =
@@ -1028,7 +1028,7 @@ void BrowserPluginGuest::SendQueuedMessages() {
 
 void BrowserPluginGuest::DidCommitProvisionalLoadForFrame(
     int64 frame_id,
-    const string16& frame_unique_name,
+    const base::string16& frame_unique_name,
     bool is_main_frame,
     const GURL& url,
     PageTransition transition_type,
@@ -1045,7 +1045,7 @@ void BrowserPluginGuest::DidStopLoading(RenderViewHost* render_view_host) {
     const char script[] = "window.addEventListener('dragstart', function() { "
                           "  window.event.preventDefault(); "
                           "});";
-    render_view_host->ExecuteJavascriptInWebFrame(string16(),
+    render_view_host->ExecuteJavascriptInWebFrame(base::string16(),
                                                   ASCIIToUTF16(script));
   }
 }
@@ -1633,8 +1633,8 @@ void BrowserPluginGuest::RunJavaScriptDialog(
     const GURL& origin_url,
     const std::string& accept_lang,
     JavaScriptMessageType javascript_message_type,
-    const string16& message_text,
-    const string16& default_prompt_text,
+    const base::string16& message_text,
+    const base::string16& default_prompt_text,
     const DialogClosedCallback& callback,
     bool* did_suppress_message) {
   base::DictionaryValue request_info;
@@ -1659,18 +1659,18 @@ void BrowserPluginGuest::RunJavaScriptDialog(
 
 void BrowserPluginGuest::RunBeforeUnloadDialog(
     WebContents* web_contents,
-    const string16& message_text,
+    const base::string16& message_text,
     bool is_reload,
     const DialogClosedCallback& callback) {
   // This is called if the guest has a beforeunload event handler.
   // This callback allows navigation to proceed.
-  callback.Run(true, string16());
+  callback.Run(true, base::string16());
 }
 
 bool BrowserPluginGuest::HandleJavaScriptDialog(
     WebContents* web_contents,
     bool accept,
-    const string16* prompt_override) {
+    const base::string16* prompt_override) {
   return false;
 }
 
diff --git a/content/browser/browser_plugin/browser_plugin_guest.h b/content/browser/browser_plugin/browser_plugin_guest.h
index 2a9c36c..6b6bf34 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.h
+++ b/content/browser/browser_plugin/browser_plugin_guest.h
@@ -147,7 +147,7 @@ class CONTENT_EXPORT BrowserPluginGuest
   // WebContentsObserver implementation.
   virtual void DidCommitProvisionalLoadForFrame(
       int64 frame_id,
-      const string16& frame_unique_name,
+      const base::string16& frame_unique_name,
       bool is_main_frame,
       const GURL& url,
       PageTransition transition_type,
@@ -161,9 +161,9 @@ class CONTENT_EXPORT BrowserPluginGuest
   // WebContentsDelegate implementation.
   virtual bool AddMessageToConsole(WebContents* source,
                                    int32 level,
-                                   const string16& message,
+                                   const base::string16& message,
                                    int32 line_no,
-                                   const string16& source_id) OVERRIDE;
+                                   const base::string16& source_id) OVERRIDE;
   // If a new window is created with target="_blank" and rel="noreferrer", then
   // this method is called, indicating that the new WebContents is ready to be
   // attached.
@@ -189,7 +189,7 @@ class CONTENT_EXPORT BrowserPluginGuest
                                       const OpenURLParams& params) OVERRIDE;
   virtual void WebContentsCreated(WebContents* source_contents,
                                   int64 source_frame_id,
-                                  const string16& frame_name,
+                                  const base::string16& frame_name,
                                   const GURL& target_url,
                                   WebContents* new_contents) OVERRIDE;
   virtual void RendererUnresponsive(WebContents* source) OVERRIDE;
@@ -208,18 +208,19 @@ class CONTENT_EXPORT BrowserPluginGuest
       const GURL& origin_url,
       const std::string& accept_lang,
       JavaScriptMessageType javascript_message_type,
-      const string16& message_text,
-      const string16& default_prompt_text,
+      const base::string16& message_text,
+      const base::string16& default_prompt_text,
       const DialogClosedCallback& callback,
       bool* did_suppress_message) OVERRIDE;
   virtual void RunBeforeUnloadDialog(
       WebContents* web_contents,
-      const string16& message_text,
+      const base::string16& message_text,
       bool is_reload,
       const DialogClosedCallback& callback) OVERRIDE;
-  virtual bool HandleJavaScriptDialog(WebContents* web_contents,
-                                      bool accept,
-                                      const string16* prompt_override) OVERRIDE;
+  virtual bool HandleJavaScriptDialog(
+      WebContents* web_contents,
+      bool accept,
+      const base::string16* prompt_override) OVERRIDE;
   virtual void CancelActiveAndPendingDialogs(
       WebContents* web_contents) OVERRIDE;
   virtual void WebContentsDestroyed(WebContents* web_contents) OVERRIDE;
diff --git a/content/browser/browser_plugin/browser_plugin_host_browsertest.cc b/content/browser/browser_plugin/browser_plugin_host_browsertest.cc
index 42c7486..cb10824 100644
--- a/content/browser/browser_plugin/browser_plugin_host_browsertest.cc
+++ b/content/browser/browser_plugin/browser_plugin_host_browsertest.cc
@@ -453,11 +453,11 @@ IN_PROC_BROWSER_TEST_F(BrowserPluginHostTest, MAYBE_EmbedderSameAfterNav) {
   // does not happen and existing embedder doesn't change in web_contents.
   GURL test_url_new(embedded_test_server()->GetURL(
       "/browser_plugin_title_change.html"));
-  const string16 expected_title = ASCIIToUTF16("done");
+  const base::string16 expected_title = ASCIIToUTF16("done");
   content::TitleWatcher title_watcher(shell()->web_contents(), expected_title);
   NavigateToURL(shell(), test_url_new);
   VLOG(0) << "Start waiting for title";
-  string16 actual_title = title_watcher.WaitAndGetTitle();
+  base::string16 actual_title = title_watcher.WaitAndGetTitle();
   EXPECT_EQ(expected_title, actual_title);
   VLOG(0) << "Done navigating to second page";
 
@@ -536,26 +536,26 @@ IN_PROC_BROWSER_TEST_F(BrowserPluginHostTest, ReloadEmbedder) {
   // the page has successfully reloaded when it goes back to 'embedder'
   // in the next step.
   {
-    const string16 expected_title = ASCIIToUTF16("modified");
+    const base::string16 expected_title = ASCIIToUTF16("modified");
     content::TitleWatcher title_watcher(test_embedder()->web_contents(),
                                         expected_title);
 
     ExecuteSyncJSFunction(rvh,
                           base::StringPrintf("SetTitle('%s');", "modified"));
 
-    string16 actual_title = title_watcher.WaitAndGetTitle();
+    base::string16 actual_title = title_watcher.WaitAndGetTitle();
     EXPECT_EQ(expected_title, actual_title);
   }
 
   // Reload the embedder page, and verify that the reload was successful.
   // Then navigate the guest to verify that the browser process does not crash.
   {
-    const string16 expected_title = ASCIIToUTF16("embedder");
+    const base::string16 expected_title = ASCIIToUTF16("embedder");
     content::TitleWatcher title_watcher(test_embedder()->web_contents(),
                                         expected_title);
 
     test_embedder()->web_contents()->GetController().Reload(false);
-    string16 actual_title = title_watcher.WaitAndGetTitle();
+    base::string16 actual_title = title_watcher.WaitAndGetTitle();
     EXPECT_EQ(expected_title, actual_title);
 
     ExecuteSyncJSFunction(
@@ -618,7 +618,7 @@ IN_PROC_BROWSER_TEST_F(BrowserPluginHostTest, MAYBE_AcceptDragEvents) {
   // This should trigger appropriate messages from the embedder to the guest,
   // and end with a drop on the guest. The guest changes title when a drop
   // happens.
-  const string16 expected_title = ASCIIToUTF16("DROPPED");
+  const base::string16 expected_title = ASCIIToUTF16("DROPPED");
   content::TitleWatcher title_watcher(test_guest()->web_contents(),
       expected_title);
 
@@ -628,7 +628,7 @@ IN_PROC_BROWSER_TEST_F(BrowserPluginHostTest, MAYBE_AcceptDragEvents) {
       blink::WebDragOperationEvery, 0);
   rvh->DragTargetDrop(gfx::Point(end_x, end_y), gfx::Point(end_x, end_y), 0);
 
-  string16 actual_title = title_watcher.WaitAndGetTitle();
+  base::string16 actual_title = title_watcher.WaitAndGetTitle();
   EXPECT_EQ(expected_title, actual_title);
 }
 
@@ -650,7 +650,7 @@ IN_PROC_BROWSER_TEST_F(BrowserPluginHostTest, PostMessage) {
   RenderViewHostImpl* rvh = static_cast<RenderViewHostImpl*>(
       test_embedder()->web_contents()->GetRenderViewHost());
   {
-    const string16 expected_title = ASCIIToUTF16("main guest");
+    const base::string16 expected_title = ASCIIToUTF16("main guest");
     content::TitleWatcher title_watcher(test_embedder()->web_contents(),
                                         expected_title);
 
@@ -661,7 +661,7 @@ IN_PROC_BROWSER_TEST_F(BrowserPluginHostTest, PostMessage) {
 
     // The title will be updated to "main guest" at the last stage of the
     // process described above.
-    string16 actual_title = title_watcher.WaitAndGetTitle();
+    base::string16 actual_title = title_watcher.WaitAndGetTitle();
     EXPECT_EQ(expected_title, actual_title);
   }
 }
@@ -678,7 +678,7 @@ IN_PROC_BROWSER_TEST_F(BrowserPluginHostTest, DISABLED_PostMessageToIFrame) {
   RenderViewHostImpl* rvh = static_cast<RenderViewHostImpl*>(
       test_embedder()->web_contents()->GetRenderViewHost());
   {
-    const string16 expected_title = ASCIIToUTF16("main guest");
+    const base::string16 expected_title = ASCIIToUTF16("main guest");
     content::TitleWatcher title_watcher(test_embedder()->web_contents(),
                                         expected_title);
 
@@ -687,7 +687,7 @@ IN_PROC_BROWSER_TEST_F(BrowserPluginHostTest, DISABLED_PostMessageToIFrame) {
 
     // The title will be updated to "main guest" at the last stage of the
     // process described above.
-    string16 actual_title = title_watcher.WaitAndGetTitle();
+    base::string16 actual_title = title_watcher.WaitAndGetTitle();
     EXPECT_EQ(expected_title, actual_title);
   }
   {
@@ -703,7 +703,7 @@ IN_PROC_BROWSER_TEST_F(BrowserPluginHostTest, DISABLED_PostMessageToIFrame) {
         base::StringPrintf(
             "CreateChildFrame('%s');", test_url.spec().c_str()));
 
-    string16 actual_title = ready_watcher.WaitAndGetTitle();
+    base::string16 actual_title = ready_watcher.WaitAndGetTitle();
     EXPECT_EQ(ASCIIToUTF16("ready"), actual_title);
 
     content::TitleWatcher iframe_watcher(test_embedder()->web_contents(),
diff --git a/content/browser/browser_plugin/test_browser_plugin_guest_delegate.cc b/content/browser/browser_plugin/test_browser_plugin_guest_delegate.cc
index dc2db35..59ae635 100644
--- a/content/browser/browser_plugin/test_browser_plugin_guest_delegate.cc
+++ b/content/browser/browser_plugin/test_browser_plugin_guest_delegate.cc
@@ -20,9 +20,9 @@ void TestBrowserPluginGuestDelegate::ResetStates() {
 
 void TestBrowserPluginGuestDelegate::AddMessageToConsole(
     int32 level,
-    const string16& message,
+    const base::string16& message,
     int32 line_no,
-    const string16& source_id) {
+    const base::string16& source_id) {
 }
 
 void TestBrowserPluginGuestDelegate::Close() {
diff --git a/content/browser/browser_plugin/test_browser_plugin_guest_delegate.h b/content/browser/browser_plugin/test_browser_plugin_guest_delegate.h
index 910ff9f..4bfae4c 100644
--- a/content/browser/browser_plugin/test_browser_plugin_guest_delegate.h
+++ b/content/browser/browser_plugin/test_browser_plugin_guest_delegate.h
@@ -22,9 +22,9 @@ class TestBrowserPluginGuestDelegate : public BrowserPluginGuestDelegate {
  private:
   // Overridden from BrowserPluginGuestDelegate:
   virtual void AddMessageToConsole(int32 level,
-                                   const string16& message,
+                                   const base::string16& message,
                                    int32 line_no,
-                                   const string16& source_id) OVERRIDE;
+                                   const base::string16& source_id) OVERRIDE;
   virtual void Close() OVERRIDE;
   virtual void GuestProcessGone(base::TerminationStatus status) OVERRIDE;
   virtual bool HandleKeyboardEvent(
diff --git a/content/browser/devtools/renderer_overrides_handler.cc b/content/browser/devtools/renderer_overrides_handler.cc
index cf3224d..28a09fc 100644
--- a/content/browser/devtools/renderer_overrides_handler.cc
+++ b/content/browser/devtools/renderer_overrides_handler.cc
@@ -293,8 +293,8 @@ RendererOverridesHandler::PageHandleJavaScriptDialog(
   bool accept;
   if (!params || !params->GetBoolean(paramAccept, &accept))
     return command->InvalidParamResponse(paramAccept);
-  string16 prompt_override;
-  string16* prompt_override_ptr = &prompt_override;
+  base::string16 prompt_override;
+  base::string16* prompt_override_ptr = &prompt_override;
   if (!params || !params->GetString(
       devtools::Page::handleJavaScriptDialog::kParamPromptText,
       prompt_override_ptr)) {
diff --git a/content/browser/devtools/worker_devtools_manager.cc b/content/browser/devtools/worker_devtools_manager.cc
index f08523b..f060881 100644
--- a/content/browser/devtools/worker_devtools_manager.cc
+++ b/content/browser/devtools/worker_devtools_manager.cc
@@ -52,13 +52,15 @@ base::LazyInstance<AgentHosts>::Leaky g_orphan_map = LAZY_INSTANCE_INITIALIZER;
 }  // namespace
 
 struct WorkerDevToolsManager::TerminatedInspectedWorker {
-  TerminatedInspectedWorker(WorkerId id, const GURL& url, const string16& name)
+  TerminatedInspectedWorker(WorkerId id,
+                            const GURL& url,
+                            const base::string16& name)
       : old_worker_id(id),
         worker_url(url),
         worker_name(name) {}
   WorkerId old_worker_id;
   GURL worker_url;
-  string16 worker_name;
+  base::string16 worker_name;
 };
 
 
@@ -202,7 +204,7 @@ class WorkerDevToolsManager::DetachedClientHosts {
 
 struct WorkerDevToolsManager::InspectedWorker {
   InspectedWorker(WorkerProcessHost* host, int route_id, const GURL& url,
-                  const string16& name)
+                  const base::string16& name)
       : host(host),
         route_id(route_id),
         worker_url(url),
@@ -210,7 +212,7 @@ struct WorkerDevToolsManager::InspectedWorker {
   WorkerProcessHost* const host;
   int const route_id;
   GURL worker_url;
-  string16 worker_name;
+  base::string16 worker_name;
 };
 
 // static
diff --git a/content/browser/dom_storage/dom_storage_message_filter.cc b/content/browser/dom_storage/dom_storage_message_filter.cc
index 3ab972c..fbc3880 100644
--- a/content/browser/dom_storage/dom_storage_message_filter.cc
+++ b/content/browser/dom_storage/dom_storage_message_filter.cc
@@ -116,8 +116,8 @@ void DOMStorageMessageFilter::OnLoadStorageArea(int connection_id,
 }
 
 void DOMStorageMessageFilter::OnSetItem(
-    int connection_id, const string16& key,
-    const string16& value, const GURL& page_url) {
+    int connection_id, const base::string16& key,
+    const base::string16& value, const GURL& page_url) {
   DCHECK(!BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK_EQ(0, connection_dispatching_message_for_);
   base::AutoReset<int> auto_reset(&connection_dispatching_message_for_,
@@ -129,20 +129,20 @@ void DOMStorageMessageFilter::OnSetItem(
 }
 
 void DOMStorageMessageFilter::OnLogGetItem(
-    int connection_id, const string16& key,
+    int connection_id, const base::string16& key,
     const base::NullableString16& value) {
   DCHECK(!BrowserThread::CurrentlyOn(BrowserThread::IO));
   host_->LogGetAreaItem(connection_id, key, value);
 }
 
 void DOMStorageMessageFilter::OnRemoveItem(
-    int connection_id, const string16& key,
+    int connection_id, const base::string16& key,
     const GURL& page_url) {
   DCHECK(!BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK_EQ(0, connection_dispatching_message_for_);
   base::AutoReset<int> auto_reset(&connection_dispatching_message_for_,
                             connection_id);
-  string16 not_used;
+  base::string16 not_used;
   host_->RemoveAreaItem(connection_id, key, page_url, &not_used);
   Send(new DOMStorageMsg_AsyncOperationComplete(true));
 }
@@ -163,8 +163,8 @@ void DOMStorageMessageFilter::OnFlushMessages() {
 
 void DOMStorageMessageFilter::OnDOMStorageItemSet(
     const DOMStorageArea* area,
-    const string16& key,
-    const string16& new_value,
+    const base::string16& key,
+    const base::string16& new_value,
     const base::NullableString16& old_value,
     const GURL& page_url) {
   SendDOMStorageEvent(area, page_url,
@@ -175,8 +175,8 @@ void DOMStorageMessageFilter::OnDOMStorageItemSet(
 
 void DOMStorageMessageFilter::OnDOMStorageItemRemoved(
     const DOMStorageArea* area,
-    const string16& key,
-    const string16& old_value,
+    const base::string16& key,
+    const base::string16& old_value,
     const GURL& page_url) {
   SendDOMStorageEvent(area, page_url,
                       base::NullableString16(key, false),
diff --git a/content/browser/dom_storage/dom_storage_message_filter.h b/content/browser/dom_storage/dom_storage_message_filter.h
index a2670ef..3c82418 100644
--- a/content/browser/dom_storage/dom_storage_message_filter.h
+++ b/content/browser/dom_storage/dom_storage_message_filter.h
@@ -53,11 +53,11 @@ class DOMStorageMessageFilter
   void OnCloseStorageArea(int connection_id);
   void OnLoadStorageArea(int connection_id, DOMStorageValuesMap* map,
                          bool* send_log_get_messages);
-  void OnSetItem(int connection_id, const string16& key,
-                 const string16& value, const GURL& page_url);
-  void OnLogGetItem(int connection_id, const string16& key,
+  void OnSetItem(int connection_id, const base::string16& key,
+                 const base::string16& value, const GURL& page_url);
+  void OnLogGetItem(int connection_id, const base::string16& key,
                     const base::NullableString16& value);
-  void OnRemoveItem(int connection_id, const string16& key,
+  void OnRemoveItem(int connection_id, const base::string16& key,
                     const GURL& page_url);
   void OnClear(int connection_id, const GURL& page_url);
   void OnFlushMessages();
@@ -66,14 +66,14 @@ class DOMStorageMessageFilter
   // sends events back to our renderer process.
   virtual void OnDOMStorageItemSet(
       const DOMStorageArea* area,
-      const string16& key,
-      const string16& new_value,
+      const base::string16& key,
+      const base::string16& new_value,
       const base::NullableString16& old_value,
       const GURL& page_url) OVERRIDE;
   virtual void OnDOMStorageItemRemoved(
       const DOMStorageArea* area,
-      const string16& key,
-      const string16& old_value,
+      const base::string16& key,
+      const base::string16& old_value,
       const GURL& page_url) OVERRIDE;
   virtual void OnDOMStorageAreaCleared(
       const DOMStorageArea* area,
diff --git a/content/browser/download/download_manager_impl_unittest.cc b/content/browser/download/download_manager_impl_unittest.cc
index aecded1..3afc41a 100644
--- a/content/browser/download/download_manager_impl_unittest.cc
+++ b/content/browser/download/download_manager_impl_unittest.cc
@@ -120,7 +120,7 @@ class MockDownloadItemImpl : public DownloadItemImpl {
   MOCK_CONST_METHOD0(CurrentSpeed, int64());
   MOCK_CONST_METHOD0(PercentComplete, int());
   MOCK_CONST_METHOD0(AllDataSaved, bool());
-  MOCK_CONST_METHOD1(MatchesQuery, bool(const string16& query));
+  MOCK_CONST_METHOD1(MatchesQuery, bool(const base::string16& query));
   MOCK_CONST_METHOD0(IsDone, bool());
   MOCK_CONST_METHOD0(GetFullPath, const base::FilePath&());
   MOCK_CONST_METHOD0(GetTargetFilePath, const base::FilePath&());
diff --git a/content/browser/download/drag_download_util.cc b/content/browser/download/drag_download_util.cc
index 41bff06..0850c3b 100644
--- a/content/browser/download/drag_download_util.cc
+++ b/content/browser/download/drag_download_util.cc
@@ -23,18 +23,18 @@ using net::FileStream;
 
 namespace content {
 
-bool ParseDownloadMetadata(const string16& metadata,
-                           string16* mime_type,
+bool ParseDownloadMetadata(const base::string16& metadata,
+                           base::string16* mime_type,
                            base::FilePath* file_name,
                            GURL* url) {
   const char16 separator = L':';
 
   size_t mime_type_end_pos = metadata.find(separator);
-  if (mime_type_end_pos == string16::npos)
+  if (mime_type_end_pos == base::string16::npos)
     return false;
 
   size_t file_name_end_pos = metadata.find(separator, mime_type_end_pos + 1);
-  if (file_name_end_pos == string16::npos)
+  if (file_name_end_pos == base::string16::npos)
     return false;
 
   GURL parsed_url = GURL(metadata.substr(file_name_end_pos + 1));
@@ -44,7 +44,7 @@ bool ParseDownloadMetadata(const string16& metadata,
   if (mime_type)
     *mime_type = metadata.substr(0, mime_type_end_pos);
   if (file_name) {
-    string16 file_name_str = metadata.substr(
+    base::string16 file_name_str = metadata.substr(
         mime_type_end_pos + 1, file_name_end_pos - mime_type_end_pos  - 1);
 #if defined(OS_WIN)
     *file_name = base::FilePath(file_name_str);
@@ -70,7 +70,7 @@ FileStream* CreateFileStreamForDrop(base::FilePath* file_path,
       new_file_path = *file_path;
     } else {
 #if defined(OS_WIN)
-      string16 suffix = ASCIIToUTF16("-") + base::IntToString16(seq);
+      base::string16 suffix = ASCIIToUTF16("-") + base::IntToString16(seq);
 #else
       std::string suffix = std::string("-") + base::IntToString(seq);
 #endif
diff --git a/content/browser/download/drag_download_util.h b/content/browser/download/drag_download_util.h
index 8b58f48..ca266efa 100644
--- a/content/browser/download/drag_download_util.h
+++ b/content/browser/download/drag_download_util.h
@@ -32,8 +32,8 @@ namespace content {
 // appropriately.
 // For example, we can have
 //   text/plain:example.txt:http://example.com/example.txt
-bool ParseDownloadMetadata(const string16& metadata,
-                           string16* mime_type,
+bool ParseDownloadMetadata(const base::string16& metadata,
+                           base::string16* mime_type,
                            base::FilePath* file_name,
                            GURL* url);
 
diff --git a/content/browser/download/save_package.h b/content/browser/download/save_package.h
index 939002e..1ab429e 100644
--- a/content/browser/download/save_package.h
+++ b/content/browser/download/save_package.h
@@ -279,7 +279,7 @@ class CONTENT_EXPORT SavePackage
   base::FilePath saved_main_directory_path_;
 
   // The title of the page the user wants to save.
-  string16 title_;
+  base::string16 title_;
 
   // Used to calculate package download speed (in files per second).
   base::TimeTicks start_tick_;
diff --git a/content/browser/download/save_package_unittest.cc b/content/browser/download/save_package_unittest.cc
index c0aa3f8..3045c42 100644
--- a/content/browser/download/save_package_unittest.cc
+++ b/content/browser/download/save_package_unittest.cc
@@ -346,7 +346,7 @@ TEST_F(SavePackageTest, MAYBE_TestEnsureMimeExtension) {
 
 static const struct SuggestedSaveNameTestCase {
   const char* page_url;
-  const string16 page_title;
+  const base::string16 page_title;
   const base::FilePath::CharType* expected_name;
   bool ensure_html_extension;
 } kSuggestedSaveNames[] = {
diff --git a/content/browser/frame_host/interstitial_page_impl.cc b/content/browser/frame_host/interstitial_page_impl.cc
index 8b249e9..27cff1f 100644
--- a/content/browser/frame_host/interstitial_page_impl.cc
+++ b/content/browser/frame_host/interstitial_page_impl.cc
@@ -431,7 +431,7 @@ void InterstitialPageImpl::DidNavigate(
 void InterstitialPageImpl::UpdateTitle(
     RenderViewHost* render_view_host,
     int32 page_id,
-    const string16& title,
+    const base::string16& title,
     base::i18n::TextDirection title_direction) {
   if (!enabled())
     return;
@@ -545,7 +545,7 @@ WebContentsView* InterstitialPageImpl::CreateWebContentsView() {
 
   int32 max_page_id = web_contents()->
       GetMaxPageIDForSiteInstance(render_view_host_->GetSiteInstance());
-  render_view_host_->CreateRenderView(string16(),
+  render_view_host_->CreateRenderView(base::string16(),
                                       MSG_ROUTING_NONE,
                                       max_page_id);
   controller_->delegate()->RenderViewForInterstitialPageCreated(
diff --git a/content/browser/frame_host/interstitial_page_impl.h b/content/browser/frame_host/interstitial_page_impl.h
index 47a127e..07695b2 100644
--- a/content/browser/frame_host/interstitial_page_impl.h
+++ b/content/browser/frame_host/interstitial_page_impl.h
@@ -112,7 +112,7 @@ class CONTENT_EXPORT InterstitialPageImpl
       const ViewHostMsg_FrameNavigate_Params& params) OVERRIDE;
   virtual void UpdateTitle(RenderViewHost* render_view_host,
                            int32 page_id,
-                           const string16& title,
+                           const base::string16& title,
                            base::i18n::TextDirection title_direction) OVERRIDE;
   virtual RendererPreferences GetRendererPrefs(
       BrowserContext* browser_context) const OVERRIDE;
@@ -246,7 +246,7 @@ class CONTENT_EXPORT InterstitialPageImpl
 
   // The original title of the contents that should be reverted to when the
   // interstitial is hidden.
-  string16 original_web_contents_title_;
+  base::string16 original_web_contents_title_;
 
   // Our RenderViewHostViewDelegate, necessary for accelerators to work.
   scoped_ptr<InterstitialPageRVHDelegateView> rvh_delegate_view_;
diff --git a/content/browser/frame_host/navigation_controller_impl.cc b/content/browser/frame_host/navigation_controller_impl.cc
index 0c6f803..a49a932 100644
--- a/content/browser/frame_host/navigation_controller_impl.cc
+++ b/content/browser/frame_host/navigation_controller_impl.cc
@@ -163,7 +163,7 @@ NavigationEntry* NavigationController::CreateNavigationEntry(
       -1,
       loaded_url,
       referrer,
-      string16(),
+      base::string16(),
       transition,
       is_renderer_initiated);
   entry->SetVirtualURL(url);
@@ -354,7 +354,7 @@ void NavigationControllerImpl::ReloadInternal(bool check_for_repost,
       // meanwhile, so we need to revert to the default title upon reload and
       // invalidate the previously cached title (SetTitle will do both).
       // See Chromium issue 96041.
-      pending_entry_->SetTitle(string16());
+      pending_entry_->SetTitle(base::string16());
 
       pending_entry_->SetTransitionType(PAGE_TRANSITION_RELOAD);
     }
diff --git a/content/browser/frame_host/navigation_controller_impl_unittest.cc b/content/browser/frame_host/navigation_controller_impl_unittest.cc
index 1f31e11..30475ec 100644
--- a/content/browser/frame_host/navigation_controller_impl_unittest.cc
+++ b/content/browser/frame_host/navigation_controller_impl_unittest.cc
@@ -921,7 +921,7 @@ TEST_F(NavigationControllerTest, LoadURL_AbortDoesntCancelPending) {
   params.frame_id = 1;
   params.is_main_frame = true;
   params.error_code = net::ERR_ABORTED;
-  params.error_description = string16();
+  params.error_description = base::string16();
   params.url = kNewURL;
   params.showing_repost_interstitial = false;
   test_rvh()->OnMessageReceived(
@@ -999,7 +999,7 @@ TEST_F(NavigationControllerTest, LoadURL_RedirectAbortDoesntShowPendingURL) {
   params.frame_id = 1;
   params.is_main_frame = true;
   params.error_code = net::ERR_ABORTED;
-  params.error_description = string16();
+  params.error_description = base::string16();
   params.url = kRedirectURL;
   params.showing_repost_interstitial = false;
   test_rvh()->OnMessageReceived(
@@ -2342,7 +2342,7 @@ TEST_F(NavigationControllerTest, RestoreNavigateAfterFailure) {
   fail_load_params.frame_id = 1;
   fail_load_params.is_main_frame = true;
   fail_load_params.error_code = net::ERR_ABORTED;
-  fail_load_params.error_description = string16();
+  fail_load_params.error_description = base::string16();
   fail_load_params.url = url;
   fail_load_params.showing_repost_interstitial = false;
   rvh->OnMessageReceived(
@@ -2897,7 +2897,7 @@ TEST_F(NavigationControllerTest, CloneAndGoBack) {
   NavigationControllerImpl& controller = controller_impl();
   const GURL url1("http://foo1");
   const GURL url2("http://foo2");
-  const string16 title(ASCIIToUTF16("Title"));
+  const base::string16 title(ASCIIToUTF16("Title"));
 
   NavigateAndCommit(url1);
   controller.GetVisibleEntry()->SetTitle(title);
@@ -2922,7 +2922,7 @@ TEST_F(NavigationControllerTest, CloneAndReload) {
   NavigationControllerImpl& controller = controller_impl();
   const GURL url1("http://foo1");
   const GURL url2("http://foo2");
-  const string16 title(ASCIIToUTF16("Title"));
+  const base::string16 title(ASCIIToUTF16("Title"));
 
   NavigateAndCommit(url1);
   controller.GetVisibleEntry()->SetTitle(title);
diff --git a/content/browser/frame_host/navigation_entry_impl.cc b/content/browser/frame_host/navigation_entry_impl.cc
index a9b37cc..d5d6fc2 100644
--- a/content/browser/frame_host/navigation_entry_impl.cc
+++ b/content/browser/frame_host/navigation_entry_impl.cc
@@ -60,7 +60,7 @@ NavigationEntryImpl::NavigationEntryImpl(SiteInstanceImpl* instance,
                                          int page_id,
                                          const GURL& url,
                                          const Referrer& referrer,
-                                         const string16& title,
+                                         const base::string16& title,
                                          PageTransition transition_type,
                                          bool is_renderer_initiated)
     : unique_id_(GetUniqueIDInConstructor()),
@@ -130,12 +130,12 @@ const GURL& NavigationEntryImpl::GetVirtualURL() const {
   return virtual_url_.is_empty() ? url_ : virtual_url_;
 }
 
-void NavigationEntryImpl::SetTitle(const string16& title) {
+void NavigationEntryImpl::SetTitle(const base::string16& title) {
   title_ = title;
   cached_display_title_.clear();
 }
 
-const string16& NavigationEntryImpl::GetTitle() const {
+const base::string16& NavigationEntryImpl::GetTitle() const {
   return title_;
 }
 
@@ -166,7 +166,7 @@ void NavigationEntryImpl::SetBindings(int bindings) {
   bindings_ = bindings;
 }
 
-const string16& NavigationEntryImpl::GetTitleForDisplay(
+const base::string16& NavigationEntryImpl::GetTitleForDisplay(
     const std::string& languages) const {
   // Most pages have real titles. Don't even bother caching anything if this is
   // the case.
@@ -179,7 +179,7 @@ const string16& NavigationEntryImpl::GetTitleForDisplay(
     return cached_display_title_;
 
   // Use the virtual URL first if any, and fall back on using the real URL.
-  string16 title;
+  base::string16 title;
   if (!virtual_url_.is_empty()) {
     title = net::FormatUrl(virtual_url_, languages);
   } else if (!url_.is_empty()) {
@@ -188,8 +188,8 @@ const string16& NavigationEntryImpl::GetTitleForDisplay(
 
   // For file:// URLs use the filename as the title, not the full path.
   if (url_.SchemeIsFile()) {
-    string16::size_type slashpos = title.rfind('/');
-    if (slashpos != string16::npos)
+    base::string16::size_type slashpos = title.rfind('/');
+    if (slashpos != base::string16::npos)
       title = title.substr(slashpos + 1);
   }
 
@@ -306,13 +306,14 @@ const std::string& NavigationEntryImpl::GetFrameToNavigate() const {
 }
 
 void NavigationEntryImpl::SetExtraData(const std::string& key,
-                                       const string16& data) {
+                                       const base::string16& data) {
   extra_data_[key] = data;
 }
 
 bool NavigationEntryImpl::GetExtraData(const std::string& key,
-                                       string16* data) const {
-  std::map<std::string, string16>::const_iterator iter = extra_data_.find(key);
+                                       base::string16* data) const {
+  std::map<std::string, base::string16>::const_iterator iter =
+      extra_data_.find(key);
   if (iter == extra_data_.end())
     return false;
   *data = iter->second;
diff --git a/content/browser/frame_host/navigation_entry_impl.h b/content/browser/frame_host/navigation_entry_impl.h
index c7f4f5f..8a51888 100644
--- a/content/browser/frame_host/navigation_entry_impl.h
+++ b/content/browser/frame_host/navigation_entry_impl.h
@@ -29,7 +29,7 @@ class CONTENT_EXPORT NavigationEntryImpl
                       int page_id,
                       const GURL& url,
                       const Referrer& referrer,
-                      const string16& title,
+                      const base::string16& title,
                       PageTransition transition_type,
                       bool is_renderer_initiated);
   virtual ~NavigationEntryImpl();
@@ -45,13 +45,13 @@ class CONTENT_EXPORT NavigationEntryImpl
   virtual const Referrer& GetReferrer() const OVERRIDE;
   virtual void SetVirtualURL(const GURL& url) OVERRIDE;
   virtual const GURL& GetVirtualURL() const OVERRIDE;
-  virtual void SetTitle(const string16& title) OVERRIDE;
-  virtual const string16& GetTitle() const OVERRIDE;
+  virtual void SetTitle(const base::string16& title) OVERRIDE;
+  virtual const base::string16& GetTitle() const OVERRIDE;
   virtual void SetPageState(const PageState& state) OVERRIDE;
   virtual const PageState& GetPageState() const OVERRIDE;
   virtual void SetPageID(int page_id) OVERRIDE;
   virtual int32 GetPageID() const OVERRIDE;
-  virtual const string16& GetTitleForDisplay(
+  virtual const base::string16& GetTitleForDisplay(
       const std::string& languages) const OVERRIDE;
   virtual bool IsViewSourceMode() const OVERRIDE;
   virtual void SetTransitionType(PageTransition transition_type) OVERRIDE;
@@ -80,9 +80,9 @@ class CONTENT_EXPORT NavigationEntryImpl
   virtual void SetFrameToNavigate(const std::string& frame_name) OVERRIDE;
   virtual const std::string& GetFrameToNavigate() const OVERRIDE;
   virtual void SetExtraData(const std::string& key,
-                            const string16& data) OVERRIDE;
+                            const base::string16& data) OVERRIDE;
   virtual bool GetExtraData(const std::string& key,
-                            string16* data) const OVERRIDE;
+                            base::string16* data) const OVERRIDE;
   virtual void ClearExtraData(const std::string& key) OVERRIDE;
   virtual void SetHttpStatusCode(int http_status_code) OVERRIDE;
   virtual int GetHttpStatusCode() const OVERRIDE;
@@ -243,7 +243,7 @@ class CONTENT_EXPORT NavigationEntryImpl
   Referrer referrer_;
   GURL virtual_url_;
   bool update_virtual_url_with_url_;
-  string16 title_;
+  base::string16 title_;
   FaviconStatus favicon_;
   PageState page_state_;
   int32 page_id_;
@@ -290,7 +290,7 @@ class CONTENT_EXPORT NavigationEntryImpl
   // us from having to do URL formatting on the URL every time the title is
   // displayed. When the URL, virtual URL, or title is set, this should be
   // cleared to force a refresh.
-  mutable string16 cached_display_title_;
+  mutable base::string16 cached_display_title_;
 
   // In case a navigation is transferred to a new RVH but the request has
   // been generated in the renderer already, this identifies the old request so
@@ -342,7 +342,7 @@ class CONTENT_EXPORT NavigationEntryImpl
   // Used to store extra data to support browser features. This member is not
   // persisted, unless specific data is taken out/put back in at save/restore
   // time (see TabNavigation for an example of this).
-  std::map<std::string, string16> extra_data_;
+  std::map<std::string, base::string16> extra_data_;
 
   // Copy and assignment is explicitly allowed for this class.
 };
diff --git a/content/browser/frame_host/navigation_entry_impl_unittest.cc b/content/browser/frame_host/navigation_entry_impl_unittest.cc
index cb742e4..488106f 100644
--- a/content/browser/frame_host/navigation_entry_impl_unittest.cc
+++ b/content/browser/frame_host/navigation_entry_impl_unittest.cc
@@ -136,7 +136,7 @@ TEST_F(NavigationEntryTest, NavigationEntryAccessors) {
   EXPECT_EQ(GURL("from2"), entry2_->GetReferrer().url);
 
   // Title
-  EXPECT_EQ(string16(), entry1_->GetTitle());
+  EXPECT_EQ(base::string16(), entry1_->GetTitle());
   EXPECT_EQ(ASCIIToUTF16("title"), entry2_->GetTitle());
   entry2_->SetTitle(ASCIIToUTF16("title2"));
   EXPECT_EQ(ASCIIToUTF16("title2"), entry2_->GetTitle());
@@ -219,8 +219,8 @@ TEST_F(NavigationEntryTest, NavigationEntryTimestamps) {
 
 // Test extra data stored in the navigation entry.
 TEST_F(NavigationEntryTest, NavigationEntryExtraData) {
-  string16 test_data = ASCIIToUTF16("my search terms");
-  string16 output;
+  base::string16 test_data = ASCIIToUTF16("my search terms");
+  base::string16 output;
   entry1_->SetExtraData("search_terms", test_data);
 
   EXPECT_FALSE(entry1_->GetExtraData("non_existent_key", &output));
@@ -233,7 +233,7 @@ TEST_F(NavigationEntryTest, NavigationEntryExtraData) {
   EXPECT_FALSE(entry1_->GetExtraData("search_terms", &output));
   EXPECT_EQ(test_data, output);
   // Using an empty string shows that the data is not present in the map.
-  string16 output2;
+  base::string16 output2;
   EXPECT_FALSE(entry1_->GetExtraData("search_terms", &output2));
   EXPECT_EQ(ASCIIToUTF16(""), output2);
 }
diff --git a/content/browser/frame_host/render_frame_host_manager_unittest.cc b/content/browser/frame_host/render_frame_host_manager_unittest.cc
index 9a4b004..69d977b 100644
--- a/content/browser/frame_host/render_frame_host_manager_unittest.cc
+++ b/content/browser/frame_host/render_frame_host_manager_unittest.cc
@@ -260,7 +260,7 @@ TEST_F(RenderFrameHostManagerTest, FilterMessagesWhileSwappedOut) {
       contents()->GetRenderManagerForTesting()->current_host());
 
   // Send an update title message and make sure it works.
-  const string16 ntp_title = ASCIIToUTF16("NTP Title");
+  const base::string16 ntp_title = ASCIIToUTF16("NTP Title");
   blink::WebTextDirection direction = blink::WebTextDirectionLeftToRight;
   EXPECT_TRUE(ntp_rvh->OnMessageReceived(
       ViewHostMsg_UpdateTitle(rvh()->GetRoutingID(), 0, ntp_title, direction)));
@@ -288,7 +288,7 @@ TEST_F(RenderFrameHostManagerTest, FilterMessagesWhileSwappedOut) {
   dest_rvh->SendNavigate(101, kDestUrl);
 
   // The new RVH should be able to update its title.
-  const string16 dest_title = ASCIIToUTF16("Google");
+  const base::string16 dest_title = ASCIIToUTF16("Google");
   EXPECT_TRUE(dest_rvh->OnMessageReceived(
       ViewHostMsg_UpdateTitle(rvh()->GetRoutingID(), 101, dest_title,
                               direction)));
@@ -308,9 +308,9 @@ TEST_F(RenderFrameHostManagerTest, FilterMessagesWhileSwappedOut) {
   MockRenderProcessHost* ntp_process_host =
       static_cast<MockRenderProcessHost*>(ntp_rvh->GetProcess());
   ntp_process_host->sink().ClearMessages();
-  const string16 msg = ASCIIToUTF16("Message");
+  const base::string16 msg = ASCIIToUTF16("Message");
   bool result = false;
-  string16 unused;
+  base::string16 unused;
   ViewHostMsg_RunBeforeUnloadConfirm before_unload_msg(
       rvh()->GetRoutingID(), kChromeURL, msg, false, &result, &unused);
   // Enable pumping for check in BrowserMessageFilter::CheckCanDispatchOnUI.
@@ -604,7 +604,7 @@ TEST_F(RenderFrameHostManagerTest, Navigate) {
   const GURL kUrl1("http://www.google.com/");
   NavigationEntryImpl entry1(
       NULL /* instance */, -1 /* page_id */, kUrl1, Referrer(),
-      string16() /* title */, PAGE_TRANSITION_TYPED,
+      base::string16() /* title */, PAGE_TRANSITION_TYPED,
       false /* is_renderer_init */);
   host = manager.Navigate(entry1);
 
@@ -626,7 +626,7 @@ TEST_F(RenderFrameHostManagerTest, Navigate) {
   NavigationEntryImpl entry2(
       NULL /* instance */, -1 /* page_id */, kUrl2,
       Referrer(kUrl1, blink::WebReferrerPolicyDefault),
-      string16() /* title */, PAGE_TRANSITION_LINK,
+      base::string16() /* title */, PAGE_TRANSITION_LINK,
       true /* is_renderer_init */);
   host = manager.Navigate(entry2);
 
@@ -646,7 +646,7 @@ TEST_F(RenderFrameHostManagerTest, Navigate) {
   NavigationEntryImpl entry3(
       NULL /* instance */, -1 /* page_id */, kUrl3,
       Referrer(kUrl2, blink::WebReferrerPolicyDefault),
-      string16() /* title */, PAGE_TRANSITION_LINK,
+      base::string16() /* title */, PAGE_TRANSITION_LINK,
       false /* is_renderer_init */);
   host = manager.Navigate(entry3);
 
@@ -693,7 +693,7 @@ TEST_F(RenderFrameHostManagerTest, NavigateWithEarlyReNavigation) {
   // 1) The first navigation. --------------------------
   const GURL kUrl1("http://www.google.com/");
   NavigationEntryImpl entry1(NULL /* instance */, -1 /* page_id */, kUrl1,
-                             Referrer(), string16() /* title */,
+                             Referrer(), base::string16() /* title */,
                              PAGE_TRANSITION_TYPED,
                              false /* is_renderer_init */);
   RenderViewHost* host = manager.Navigate(entry1);
@@ -721,7 +721,7 @@ TEST_F(RenderFrameHostManagerTest, NavigateWithEarlyReNavigation) {
   const GURL kUrl2("http://www.example.com");
   NavigationEntryImpl entry2(
       NULL /* instance */, -1 /* page_id */, kUrl2, Referrer(),
-      string16() /* title */, PAGE_TRANSITION_TYPED,
+      base::string16() /* title */, PAGE_TRANSITION_TYPED,
       false /* is_renderer_init */);
   RenderViewHostImpl* host2 = static_cast<RenderViewHostImpl*>(
       manager.Navigate(entry2));
@@ -772,7 +772,7 @@ TEST_F(RenderFrameHostManagerTest, NavigateWithEarlyReNavigation) {
   // 3) Cross-site navigate to next site before 2) has committed. --------------
   const GURL kUrl3("http://webkit.org/");
   NavigationEntryImpl entry3(NULL /* instance */, -1 /* page_id */, kUrl3,
-                             Referrer(), string16() /* title */,
+                             Referrer(), base::string16() /* title */,
                              PAGE_TRANSITION_TYPED,
                              false /* is_renderer_init */);
   test_process_host->sink().ClearMessages();
@@ -836,7 +836,7 @@ TEST_F(RenderFrameHostManagerTest, WebUI) {
 
   const GURL kUrl("chrome://foo");
   NavigationEntryImpl entry(NULL /* instance */, -1 /* page_id */, kUrl,
-                            Referrer(), string16() /* title */,
+                            Referrer(), base::string16() /* title */,
                             PAGE_TRANSITION_TYPED,
                             false /* is_renderer_init */);
   RenderViewHost* host = manager.Navigate(entry);
@@ -880,12 +880,12 @@ TEST_F(RenderFrameHostManagerTest, WebUIInNewTab) {
   manager1.Init(
       browser_context(), blank_instance, MSG_ROUTING_NONE, MSG_ROUTING_NONE);
   // Test the case that new RVH is considered live.
-  manager1.current_host()->CreateRenderView(string16(), -1, -1);
+  manager1.current_host()->CreateRenderView(base::string16(), -1, -1);
 
   // Navigate to a WebUI page.
   const GURL kUrl1("chrome://foo");
   NavigationEntryImpl entry1(NULL /* instance */, -1 /* page_id */, kUrl1,
-                             Referrer(), string16() /* title */,
+                             Referrer(), base::string16() /* title */,
                              PAGE_TRANSITION_TYPED,
                              false /* is_renderer_init */);
   RenderViewHost* host1 = manager1.Navigate(entry1);
@@ -911,11 +911,11 @@ TEST_F(RenderFrameHostManagerTest, WebUIInNewTab) {
       browser_context(), webui_instance, MSG_ROUTING_NONE, MSG_ROUTING_NONE);
   // Make sure the new RVH is considered live.  This is usually done in
   // RenderWidgetHost::Init when opening a new tab from a link.
-  manager2.current_host()->CreateRenderView(string16(), -1, -1);
+  manager2.current_host()->CreateRenderView(base::string16(), -1, -1);
 
   const GURL kUrl2("chrome://foo/bar");
   NavigationEntryImpl entry2(NULL /* instance */, -1 /* page_id */, kUrl2,
-                             Referrer(), string16() /* title */,
+                             Referrer(), base::string16() /* title */,
                              PAGE_TRANSITION_LINK,
                              true /* is_renderer_init */);
   RenderViewHost* host2 = manager2.Navigate(entry2);
@@ -1107,7 +1107,7 @@ TEST_F(RenderFrameHostManagerTest, CleanUpSwappedOutRVHOnProcessCrash) {
   contents()->SetOpener(opener1.get());
 
   // Make sure the new opener RVH is considered live.
-  opener1_manager->current_host()->CreateRenderView(string16(), -1, -1);
+  opener1_manager->current_host()->CreateRenderView(base::string16(), -1, -1);
 
   // Use a cross-process navigation in the opener to swap out the old RVH.
   EXPECT_FALSE(opener1_manager->GetSwappedOutRenderViewHost(
@@ -1202,7 +1202,7 @@ TEST_F(RenderFrameHostManagerTest, NoSwapOnGuestNavigations) {
   const GURL kUrl1("http://www.google.com/");
   NavigationEntryImpl entry1(
       NULL /* instance */, -1 /* page_id */, kUrl1, Referrer(),
-      string16() /* title */, PAGE_TRANSITION_TYPED,
+      base::string16() /* title */, PAGE_TRANSITION_TYPED,
       false /* is_renderer_init */);
   host = manager.Navigate(entry1);
 
@@ -1225,7 +1225,7 @@ TEST_F(RenderFrameHostManagerTest, NoSwapOnGuestNavigations) {
   NavigationEntryImpl entry2(
       NULL /* instance */, -1 /* page_id */, kUrl2,
       Referrer(kUrl1, blink::WebReferrerPolicyDefault),
-      string16() /* title */, PAGE_TRANSITION_LINK,
+      base::string16() /* title */, PAGE_TRANSITION_LINK,
       true /* is_renderer_init */);
   host = manager.Navigate(entry2);
 
@@ -1264,7 +1264,7 @@ TEST_F(RenderFrameHostManagerTest, NavigateWithEarlyClose) {
   // 1) The first navigation. --------------------------
   const GURL kUrl1("http://www.google.com/");
   NavigationEntryImpl entry1(NULL /* instance */, -1 /* page_id */, kUrl1,
-                             Referrer(), string16() /* title */,
+                             Referrer(), base::string16() /* title */,
                              PAGE_TRANSITION_TYPED,
                              false /* is_renderer_init */);
   RenderViewHost* host = manager.Navigate(entry1);
@@ -1291,7 +1291,7 @@ TEST_F(RenderFrameHostManagerTest, NavigateWithEarlyClose) {
   const GURL kUrl2("http://www.example.com");
   NavigationEntryImpl entry2(
       NULL /* instance */, -1 /* page_id */, kUrl2, Referrer(),
-      string16() /* title */, PAGE_TRANSITION_TYPED,
+      base::string16() /* title */, PAGE_TRANSITION_TYPED,
       false /* is_renderer_init */);
   RenderViewHostImpl* host2 = static_cast<RenderViewHostImpl*>(
       manager.Navigate(entry2));
diff --git a/content/browser/gamepad/gamepad_platform_data_fetcher_linux.cc b/content/browser/gamepad/gamepad_platform_data_fetcher_linux.cc
index ba048ae..148ec49 100644
--- a/content/browser/gamepad/gamepad_platform_data_fetcher_linux.cc
+++ b/content/browser/gamepad/gamepad_platform_data_fetcher_linux.cc
@@ -187,7 +187,7 @@ void GamepadPlatformDataFetcherLinux::RefreshDevice(udev_device* dev) {
         vendor_id,
         product_id);
     TruncateUTF8ToByteSize(id, WebGamepad::idLengthCap - 1, &id);
-    string16 tmp16 = UTF8ToUTF16(id);
+    base::string16 tmp16 = UTF8ToUTF16(id);
     memset(pad.id, 0, sizeof(pad.id));
     tmp16.copy(pad.id, arraysize(pad.id) - 1);
 
diff --git a/content/browser/geolocation/fake_access_token_store.cc b/content/browser/geolocation/fake_access_token_store.cc
index 9f9f61b..0e5fe40 100644
--- a/content/browser/geolocation/fake_access_token_store.cc
+++ b/content/browser/geolocation/fake_access_token_store.cc
@@ -45,7 +45,7 @@ void FakeAccessTokenStore::DefaultLoadAccessTokens(
 }
 
 void FakeAccessTokenStore::DefaultSaveAccessToken(
-    const GURL& server_url, const string16& access_token) {
+    const GURL& server_url, const base::string16& access_token) {
   DCHECK(server_url.is_valid());
   access_token_set_[server_url] = access_token;
 }
diff --git a/content/browser/geolocation/fake_access_token_store.h b/content/browser/geolocation/fake_access_token_store.h
index 4d0867b..30a0185 100644
--- a/content/browser/geolocation/fake_access_token_store.h
+++ b/content/browser/geolocation/fake_access_token_store.h
@@ -23,12 +23,13 @@ class FakeAccessTokenStore : public AccessTokenStore {
   MOCK_METHOD1(LoadAccessTokens,
                void(const LoadAccessTokensCallbackType& callback));
   MOCK_METHOD2(SaveAccessToken,
-               void(const GURL& server_url, const string16& access_token));
+               void(const GURL& server_url,
+                    const base::string16& access_token));
 
   void DefaultLoadAccessTokens(const LoadAccessTokensCallbackType& callback);
 
   void DefaultSaveAccessToken(const GURL& server_url,
-                              const string16& access_token);
+                              const base::string16& access_token);
 
   AccessTokenSet access_token_set_;
   LoadAccessTokensCallbackType callback_;
diff --git a/content/browser/geolocation/location_arbitrator_impl.cc b/content/browser/geolocation/location_arbitrator_impl.cc
index 37c34ee..b8ed8c4 100644
--- a/content/browser/geolocation/location_arbitrator_impl.cc
+++ b/content/browser/geolocation/location_arbitrator_impl.cc
@@ -149,7 +149,7 @@ LocationProvider* LocationArbitratorImpl::NewNetworkLocationProvider(
     AccessTokenStore* access_token_store,
     net::URLRequestContextGetter* context,
     const GURL& url,
-    const string16& access_token) {
+    const base::string16& access_token) {
 #if defined(OS_ANDROID)
   // Android uses its own SystemLocationProvider.
   return NULL;
diff --git a/content/browser/geolocation/location_arbitrator_impl.h b/content/browser/geolocation/location_arbitrator_impl.h
index 45910552..e756f5e 100644
--- a/content/browser/geolocation/location_arbitrator_impl.h
+++ b/content/browser/geolocation/location_arbitrator_impl.h
@@ -57,7 +57,7 @@ class CONTENT_EXPORT LocationArbitratorImpl : public LocationArbitrator {
       AccessTokenStore* access_token_store,
       net::URLRequestContextGetter* context,
       const GURL& url,
-      const string16& access_token);
+      const base::string16& access_token);
   virtual LocationProvider* NewSystemLocationProvider();
   virtual base::Time GetTimeNow() const;
 
diff --git a/content/browser/geolocation/location_arbitrator_impl_unittest.cc b/content/browser/geolocation/location_arbitrator_impl_unittest.cc
index 02df431..81df7a4 100644
--- a/content/browser/geolocation/location_arbitrator_impl_unittest.cc
+++ b/content/browser/geolocation/location_arbitrator_impl_unittest.cc
@@ -85,7 +85,7 @@ class TestingLocationArbitrator : public LocationArbitratorImpl {
       AccessTokenStore* access_token_store,
       net::URLRequestContextGetter* context,
       const GURL& url,
-      const string16& access_token) OVERRIDE {
+      const base::string16& access_token) OVERRIDE {
     return new MockLocationProvider(&cell_);
   }
 
diff --git a/content/browser/geolocation/network_location_provider.cc b/content/browser/geolocation/network_location_provider.cc
index 678edb2..efc68a7 100644
--- a/content/browser/geolocation/network_location_provider.cc
+++ b/content/browser/geolocation/network_location_provider.cc
@@ -27,7 +27,7 @@ bool NetworkLocationProvider::PositionCache::CachePosition(
     const WifiData& wifi_data,
     const Geoposition& position) {
   // Check that we can generate a valid key for the wifi data.
-  string16 key;
+  base::string16 key;
   if (!MakeKey(wifi_data, &key)) {
     return false;
   }
@@ -57,7 +57,7 @@ bool NetworkLocationProvider::PositionCache::CachePosition(
 // the cached position if available, NULL otherwise.
 const Geoposition* NetworkLocationProvider::PositionCache::FindPosition(
     const WifiData& wifi_data) {
-  string16 key;
+  base::string16 key;
   if (!MakeKey(wifi_data, &key)) {
     return NULL;
   }
@@ -71,13 +71,13 @@ const Geoposition* NetworkLocationProvider::PositionCache::FindPosition(
 // static
 bool NetworkLocationProvider::PositionCache::MakeKey(
     const WifiData& wifi_data,
-    string16* key) {
+    base::string16* key) {
   // Currently we use only WiFi data and base the key only on the MAC addresses.
   DCHECK(key);
   key->clear();
   const size_t kCharsPerMacAddress = 6 * 3 + 1;  // e.g. "11:22:33:44:55:66|"
   key->reserve(wifi_data.access_point_data.size() * kCharsPerMacAddress);
-  const string16 separator(ASCIIToUTF16("|"));
+  const base::string16 separator(ASCIIToUTF16("|"));
   for (WifiData::AccessPointDataSet::const_iterator iter =
        wifi_data.access_point_data.begin();
        iter != wifi_data.access_point_data.end();
@@ -96,7 +96,7 @@ LocationProviderBase* NewNetworkLocationProvider(
     AccessTokenStore* access_token_store,
     net::URLRequestContextGetter* context,
     const GURL& url,
-    const string16& access_token) {
+    const base::string16& access_token) {
   return new NetworkLocationProvider(
       access_token_store, context, url, access_token);
 }
@@ -106,7 +106,7 @@ NetworkLocationProvider::NetworkLocationProvider(
     AccessTokenStore* access_token_store,
     net::URLRequestContextGetter* url_context_getter,
     const GURL& url,
-    const string16& access_token)
+    const base::string16& access_token)
     : access_token_store_(access_token_store),
       wifi_data_provider_(NULL),
       wifi_data_update_callback_(
@@ -163,7 +163,7 @@ void NetworkLocationProvider::WifiDataUpdateAvailable(
 void NetworkLocationProvider::LocationResponseAvailable(
     const Geoposition& position,
     bool server_error,
-    const string16& access_token,
+    const base::string16& access_token,
     const WifiData& wifi_data) {
   DCHECK(CalledOnValidThread());
   // Record the position and update our cache.
diff --git a/content/browser/geolocation/network_location_provider.h b/content/browser/geolocation/network_location_provider.h
index d5f3e99..710fd3f 100644
--- a/content/browser/geolocation/network_location_provider.h
+++ b/content/browser/geolocation/network_location_provider.h
@@ -54,12 +54,12 @@ class NetworkLocationProvider
     // Makes the key for the map of cached positions, using a set of
     // data. Returns true if a good key was generated, false otherwise.
     static bool MakeKey(const WifiData& wifi_data,
-                        string16* key);
+                        base::string16* key);
 
     // The cache of positions. This is stored as a map keyed on a string that
     // represents a set of data, and a list to provide
     // least-recently-added eviction.
-    typedef std::map<string16, Geoposition> CacheMap;
+    typedef std::map<base::string16, Geoposition> CacheMap;
     CacheMap cache_;
     typedef std::list<CacheMap::iterator> CacheAgeList;
     CacheAgeList cache_age_list_;  // Oldest first.
@@ -68,7 +68,7 @@ class NetworkLocationProvider
   NetworkLocationProvider(AccessTokenStore* access_token_store,
                           net::URLRequestContextGetter* context,
                           const GURL& url,
-                          const string16& access_token);
+                          const base::string16& access_token);
   virtual ~NetworkLocationProvider();
 
   // LocationProvider implementation
@@ -92,7 +92,7 @@ class NetworkLocationProvider
 
   void LocationResponseAvailable(const Geoposition& position,
                                  bool server_error,
-                                 const string16& access_token,
+                                 const base::string16& access_token,
                                  const WifiData& wifi_data);
 
   scoped_refptr<AccessTokenStore> access_token_store_;
@@ -111,7 +111,7 @@ class NetworkLocationProvider
 
   // Cached value loaded from the token store or set by a previous server
   // response, and sent in each subsequent network request.
-  string16 access_token_;
+  base::string16 access_token_;
 
   // The current best position estimate.
   Geoposition position_;
@@ -138,7 +138,7 @@ CONTENT_EXPORT LocationProviderBase* NewNetworkLocationProvider(
     AccessTokenStore* access_token_store,
     net::URLRequestContextGetter* context,
     const GURL& url,
-    const string16& access_token);
+    const base::string16& access_token);
 
 }  // namespace content
 
diff --git a/content/browser/geolocation/network_location_request.cc b/content/browser/geolocation/network_location_request.cc
index 2e269b3..3ed7092 100644
--- a/content/browser/geolocation/network_location_request.cc
+++ b/content/browser/geolocation/network_location_request.cc
@@ -72,7 +72,7 @@ GURL FormRequestURL(const GURL& url);
 
 void FormUploadData(const WifiData& wifi_data,
                     const base::Time& timestamp,
-                    const string16& access_token,
+                    const base::string16& access_token,
                     std::string* upload_data);
 
 // Attempts to extract a position from the response. Detects and indicates
@@ -83,7 +83,7 @@ void GetLocationFromResponse(bool http_post_result,
                              const base::Time& timestamp,
                              const GURL& server_url,
                              Geoposition* position,
-                             string16* access_token);
+                             base::string16* access_token);
 
 // Parses the server response body. Returns true if parsing was successful.
 // Sets |*position| to the parsed location if a valid fix was received,
@@ -91,7 +91,7 @@ void GetLocationFromResponse(bool http_post_result,
 bool ParseServerResponse(const std::string& response_body,
                          const base::Time& timestamp,
                          Geoposition* position,
-                         string16* access_token);
+                         base::string16* access_token);
 void AddWifiData(const WifiData& wifi_data,
                  int age_milliseconds,
                  base::DictionaryValue* request);
@@ -111,7 +111,7 @@ NetworkLocationRequest::NetworkLocationRequest(
 NetworkLocationRequest::~NetworkLocationRequest() {
 }
 
-bool NetworkLocationRequest::MakeRequest(const string16& access_token,
+bool NetworkLocationRequest::MakeRequest(const base::string16& access_token,
                                          const WifiData& wifi_data,
                                          const base::Time& timestamp) {
   RecordUmaEvent(NETWORK_LOCATION_REQUEST_EVENT_REQUEST_START);
@@ -150,7 +150,7 @@ void NetworkLocationRequest::OnURLFetchComplete(
   RecordUmaResponseCode(response_code);
 
   Geoposition position;
-  string16 access_token;
+  base::string16 access_token;
   std::string data;
   source->GetResponseAsString(&data);
   GetLocationFromResponse(status.is_success(),
@@ -207,7 +207,7 @@ GURL FormRequestURL(const GURL& url) {
 
 void FormUploadData(const WifiData& wifi_data,
                     const base::Time& timestamp,
-                    const string16& access_token,
+                    const base::string16& access_token,
                     std::string* upload_data) {
   int age = kint32min;  // Invalid so AddInteger() will ignore.
   if (!timestamp.is_null()) {
@@ -291,7 +291,7 @@ void GetLocationFromResponse(bool http_post_result,
                              const base::Time& timestamp,
                              const GURL& server_url,
                              Geoposition* position,
-                             string16* access_token) {
+                             base::string16* access_token) {
   DCHECK(position);
   DCHECK(access_token);
 
@@ -351,7 +351,7 @@ bool GetAsDouble(const base::DictionaryValue& object,
 bool ParseServerResponse(const std::string& response_body,
                          const base::Time& timestamp,
                          Geoposition* position,
-                         string16* access_token) {
+                         base::string16* access_token) {
   DCHECK(position);
   DCHECK(!position->Validate());
   DCHECK(position->error_code == Geoposition::ERROR_CODE_NONE);
diff --git a/content/browser/geolocation/network_location_request.h b/content/browser/geolocation/network_location_request.h
index 38aaf3e..6fea08b 100644
--- a/content/browser/geolocation/network_location_request.h
+++ b/content/browser/geolocation/network_location_request.h
@@ -33,7 +33,7 @@ class NetworkLocationRequest : private net::URLFetcherDelegate {
   // server or network error - either no response or a 500 error code.
   typedef base::Callback<void(const Geoposition& /* position */,
                               bool /* server_error */,
-                              const string16& /* access_token */,
+                              const base::string16& /* access_token */,
                               const WifiData& /* wifi_data */)>
       LocationResponseCallback;
 
@@ -45,7 +45,7 @@ class NetworkLocationRequest : private net::URLFetcherDelegate {
 
   // Makes a new request. Returns true if the new request was successfully
   // started. In all cases, any currently pending request will be canceled.
-  bool MakeRequest(const string16& access_token,
+  bool MakeRequest(const base::string16& access_token,
                    const WifiData& wifi_data,
                    const base::Time& timestamp);
 
diff --git a/content/browser/geolocation/wifi_data.h b/content/browser/geolocation/wifi_data.h
index a24e42e..72bc306 100644
--- a/content/browser/geolocation/wifi_data.h
+++ b/content/browser/geolocation/wifi_data.h
@@ -19,11 +19,11 @@ struct CONTENT_EXPORT AccessPointData {
   ~AccessPointData();
 
   // MAC address, formatted as per MacAddressAsString16.
-  string16 mac_address;
+  base::string16 mac_address;
   int radio_signal_strength;  // Measured in dBm
   int channel;
   int signal_to_noise;  // Ratio in dB
-  string16 ssid;   // Network identifier
+  base::string16 ssid;   // Network identifier
 };
 
 // This is to allow AccessPointData to be used in std::set. We order
diff --git a/content/browser/geolocation/wifi_data_provider_common.cc b/content/browser/geolocation/wifi_data_provider_common.cc
index 31f969c..9c2cbae 100644
--- a/content/browser/geolocation/wifi_data_provider_common.cc
+++ b/content/browser/geolocation/wifi_data_provider_common.cc
@@ -10,7 +10,7 @@
 
 namespace content {
 
-string16 MacAddressAsString16(const uint8 mac_as_int[6]) {
+base::string16 MacAddressAsString16(const uint8 mac_as_int[6]) {
   // mac_as_int is big-endian. Write in byte chunks.
   // Format is XX-XX-XX-XX-XX-XX.
   static const char* const kMacFormatString =
diff --git a/content/browser/geolocation/wifi_data_provider_common.h b/content/browser/geolocation/wifi_data_provider_common.h
index c42b4c2..befdb69 100644
--- a/content/browser/geolocation/wifi_data_provider_common.h
+++ b/content/browser/geolocation/wifi_data_provider_common.h
@@ -18,7 +18,7 @@
 namespace content {
 
 // Converts a MAC address stored as an array of uint8 to a string.
-string16 MacAddressAsString16(const uint8 mac_as_int[6]);
+base::string16 MacAddressAsString16(const uint8 mac_as_int[6]);
 
 // Base class to promote code sharing between platform specific wifi data
 // providers. It's optional for specific platforms to derive this, but if they
diff --git a/content/browser/geolocation/wifi_data_provider_win.cc b/content/browser/geolocation/wifi_data_provider_win.cc
index 8efb191..ed69865 100644
--- a/content/browser/geolocation/wifi_data_provider_win.cc
+++ b/content/browser/geolocation/wifi_data_provider_win.cc
@@ -127,15 +127,15 @@ class WindowsNdisApi : public WifiDataProviderCommon::WlanApiInterface {
 
  private:
   static bool GetInterfacesNDIS(
-      std::vector<string16>* interface_service_names_out);
+      std::vector<base::string16>* interface_service_names_out);
 
   // Swaps in content of the vector passed
-  explicit WindowsNdisApi(std::vector<string16>* interface_service_names);
+  explicit WindowsNdisApi(std::vector<base::string16>* interface_service_names);
 
   bool GetInterfaceDataNDIS(HANDLE adapter_handle,
                             WifiData::AccessPointDataSet* data);
   // NDIS variables.
-  std::vector<string16> interface_service_names_;
+  std::vector<base::string16> interface_service_names_;
 
   // Remembers scan result buffer size across calls.
   int oid_buffer_size_;
@@ -144,9 +144,9 @@ class WindowsNdisApi : public WifiDataProviderCommon::WlanApiInterface {
 // Extracts data for an access point and converts to Gears format.
 bool GetNetworkData(const WLAN_BSS_ENTRY& bss_entry,
                     AccessPointData* access_point_data);
-bool UndefineDosDevice(const string16& device_name);
-bool DefineDosDeviceIfNotExists(const string16& device_name);
-HANDLE GetFileHandle(const string16& device_name);
+bool UndefineDosDevice(const base::string16& device_name);
+bool DefineDosDeviceIfNotExists(const base::string16& device_name);
+HANDLE GetFileHandle(const base::string16& device_name);
 // Makes the OID query and returns a Win32 error code.
 int PerformQuery(HANDLE adapter_handle,
                  BYTE* buffer,
@@ -155,7 +155,7 @@ int PerformQuery(HANDLE adapter_handle,
 bool ResizeBuffer(int requested_size, scoped_ptr_malloc<BYTE>* buffer);
 // Gets the system directory and appends a trailing slash if not already
 // present.
-bool GetSystemDirectory(string16* path);
+bool GetSystemDirectory(base::string16* path);
 }  // namespace
 
 WifiDataProviderImplBase* WifiDataProvider::DefaultFactoryFunction() {
@@ -202,12 +202,12 @@ WindowsWlanApi* WindowsWlanApi::Create() {
   if (base::win::GetVersion() < base::win::VERSION_VISTA)
     return NULL;
   // We use an absolute path to load the DLL to avoid DLL preloading attacks.
-  string16 system_directory;
+  base::string16 system_directory;
   if (!GetSystemDirectory(&system_directory)) {
     return NULL;
   }
   DCHECK(!system_directory.empty());
-  string16 dll_path = system_directory + L"wlanapi.dll";
+  base::string16 dll_path = system_directory + L"wlanapi.dll";
   HINSTANCE library = LoadLibraryEx(dll_path.c_str(),
                                     NULL,
                                     LOAD_WITH_ALTERED_SEARCH_PATH);
@@ -359,7 +359,7 @@ int WindowsWlanApi::GetInterfaceDataWLAN(
 
 // WindowsNdisApi
 WindowsNdisApi::WindowsNdisApi(
-    std::vector<string16>* interface_service_names)
+    std::vector<base::string16>* interface_service_names)
     : oid_buffer_size_(kInitialBufferSize) {
   DCHECK(!interface_service_names->empty());
   interface_service_names_.swap(*interface_service_names);
@@ -369,7 +369,7 @@ WindowsNdisApi::~WindowsNdisApi() {
 }
 
 WindowsNdisApi* WindowsNdisApi::Create() {
-  std::vector<string16> interface_service_names;
+  std::vector<base::string16> interface_service_names;
   if (GetInterfacesNDIS(&interface_service_names)) {
     return new WindowsNdisApi(&interface_service_names);
   }
@@ -412,7 +412,7 @@ bool WindowsNdisApi::GetAccessPointData(WifiData::AccessPointDataSet* data) {
 }
 
 bool WindowsNdisApi::GetInterfacesNDIS(
-    std::vector<string16>* interface_service_names_out) {
+    std::vector<base::string16>* interface_service_names_out) {
   HKEY network_cards_key = NULL;
   if (RegOpenKeyEx(
       HKEY_LOCAL_MACHINE,
@@ -530,18 +530,18 @@ bool GetNetworkData(const WLAN_BSS_ENTRY& bss_entry,
   return true;
 }
 
-bool UndefineDosDevice(const string16& device_name) {
+bool UndefineDosDevice(const base::string16& device_name) {
   // We remove only the mapping we use, that is \Device\<device_name>.
-  string16 target_path = L"\\Device\\" + device_name;
+  base::string16 target_path = L"\\Device\\" + device_name;
   return DefineDosDevice(
       DDD_RAW_TARGET_PATH | DDD_REMOVE_DEFINITION | DDD_EXACT_MATCH_ON_REMOVE,
       device_name.c_str(),
       target_path.c_str()) == TRUE;
 }
 
-bool DefineDosDeviceIfNotExists(const string16& device_name) {
+bool DefineDosDeviceIfNotExists(const base::string16& device_name) {
   // We create a DOS device name for the device at \Device\<device_name>.
-  string16 target_path = L"\\Device\\" + device_name;
+  base::string16 target_path = L"\\Device\\" + device_name;
 
   TCHAR target[kStringLength];
   if (QueryDosDevice(device_name.c_str(), target, kStringLength) > 0 &&
@@ -565,10 +565,10 @@ bool DefineDosDeviceIfNotExists(const string16& device_name) {
       target_path.compare(target) == 0;
 }
 
-HANDLE GetFileHandle(const string16& device_name) {
+HANDLE GetFileHandle(const base::string16& device_name) {
   // We access a device with DOS path \Device\<device_name> at
   // \\.\<device_name>.
-  string16 formatted_device_name = L"\\\\.\\" + device_name;
+  base::string16 formatted_device_name = L"\\\\.\\" + device_name;
 
   return CreateFile(formatted_device_name.c_str(),
                     GENERIC_READ,
@@ -610,7 +610,7 @@ bool ResizeBuffer(int requested_size, scoped_ptr_malloc<BYTE>* buffer) {
   return buffer != NULL;
 }
 
-bool GetSystemDirectory(string16* path) {
+bool GetSystemDirectory(base::string16* path) {
   DCHECK(path);
   // Return value includes terminating NULL.
   int buffer_size = ::GetSystemDirectory(NULL, 0);
diff --git a/content/browser/gpu/gpu_process_host.cc b/content/browser/gpu/gpu_process_host.cc
index 26b33d4..53e9841 100644
--- a/content/browser/gpu/gpu_process_host.cc
+++ b/content/browser/gpu/gpu_process_host.cc
@@ -252,7 +252,7 @@ class GpuSandboxedProcessLauncherDelegate
 #endif
 
     if (cmd_line_->HasSwitch(switches::kEnableLogging)) {
-      string16 log_file_path = logging::GetLogFileFullPath();
+      base::string16 log_file_path = logging::GetLogFileFullPath();
       if (!log_file_path.empty()) {
         result = policy->AddRule(sandbox::TargetPolicy::SUBSYS_FILES,
                                  sandbox::TargetPolicy::FILES_ALLOW_ANY,
diff --git a/content/browser/indexed_db/indexed_db_backing_store.cc b/content/browser/indexed_db/indexed_db_backing_store.cc
index 766d6a4..92f4b22 100644
--- a/content/browser/indexed_db/indexed_db_backing_store.cc
+++ b/content/browser/indexed_db/indexed_db_backing_store.cc
@@ -157,7 +157,7 @@ static void PutVarInt(LevelDBTransaction* transaction,
 template <typename DBOrTransaction>
 WARN_UNUSED_RESULT static bool GetString(DBOrTransaction* db,
                                          const StringPiece& key,
-                                         string16* found_string,
+                                         base::string16* found_string,
                                          bool* found) {
   std::string result;
   *found = false;
@@ -172,7 +172,7 @@ WARN_UNUSED_RESULT static bool GetString(DBOrTransaction* db,
 
 static void PutString(LevelDBTransaction* transaction,
                       const StringPiece& key,
-                      const string16& value) {
+                      const base::string16& value) {
   std::string buffer;
   EncodeString(value, &buffer);
   transaction->Put(key, &buffer);
@@ -653,8 +653,8 @@ scoped_refptr<IndexedDBBackingStore> IndexedDBBackingStore::Create(
   return backing_store;
 }
 
-std::vector<string16> IndexedDBBackingStore::GetDatabaseNames() {
-  std::vector<string16> found_names;
+std::vector<base::string16> IndexedDBBackingStore::GetDatabaseNames() {
+  std::vector<base::string16> found_names;
   const std::string start_key =
       DatabaseNameKey::EncodeMinKeyForOrigin(origin_identifier_);
   const std::string stop_key =
@@ -678,7 +678,7 @@ std::vector<string16> IndexedDBBackingStore::GetDatabaseNames() {
 }
 
 bool IndexedDBBackingStore::GetIDBDatabaseMetaData(
-    const string16& name,
+    const base::string16& name,
     IndexedDBDatabaseMetadata* metadata,
     bool* found) {
   const std::string key = DatabaseNameKey::Encode(origin_identifier_, name);
@@ -755,10 +755,11 @@ WARN_UNUSED_RESULT static bool GetNewDatabaseId(LevelDBTransaction* transaction,
   return true;
 }
 
-bool IndexedDBBackingStore::CreateIDBDatabaseMetaData(const string16& name,
-                                                      const string16& version,
-                                                      int64 int_version,
-                                                      int64* row_id) {
+bool IndexedDBBackingStore::CreateIDBDatabaseMetaData(
+    const base::string16& name,
+    const base::string16& version,
+    int64 int_version,
+    int64* row_id) {
   scoped_refptr<LevelDBTransaction> transaction =
       new LevelDBTransaction(db_.get());
 
@@ -811,7 +812,7 @@ static void DeleteRange(LevelDBTransaction* transaction,
     transaction->Remove(it->Key());
 }
 
-bool IndexedDBBackingStore::DeleteDatabase(const string16& name) {
+bool IndexedDBBackingStore::DeleteDatabase(const base::string16& name) {
   IDB_TRACE("IndexedDBBackingStore::DeleteDatabase");
   scoped_ptr<LevelDBWriteOnlyTransaction> transaction =
       LevelDBWriteOnlyTransaction::Create(db_.get());
@@ -895,7 +896,7 @@ bool IndexedDBBackingStore::GetObjectStores(
 
     // TODO(jsbell): Do this by direct key lookup rather than iteration, to
     // simplify.
-    string16 object_store_name;
+    base::string16 object_store_name;
     {
       StringPiece slice(it->Value());
       if (!DecodeString(&slice, &object_store_name) || !slice.empty())
@@ -1049,7 +1050,7 @@ bool IndexedDBBackingStore::CreateObjectStore(
     IndexedDBBackingStore::Transaction* transaction,
     int64 database_id,
     int64 object_store_id,
-    const string16& name,
+    const base::string16& name,
     const IndexedDBKeyPath& key_path,
     bool auto_increment) {
   IDB_TRACE("IndexedDBBackingStore::CreateObjectStore");
@@ -1103,7 +1104,7 @@ bool IndexedDBBackingStore::DeleteObjectStore(
     return false;
   LevelDBTransaction* leveldb_transaction = transaction->transaction();
 
-  string16 object_store_name;
+  base::string16 object_store_name;
   bool found = false;
   bool ok = GetString(
       leveldb_transaction,
@@ -1473,7 +1474,7 @@ bool IndexedDBBackingStore::GetIndexes(
     // TODO(jsbell): Do this by direct key lookup rather than iteration, to
     // simplify.
     int64 index_id = meta_data_key.IndexId();
-    string16 index_name;
+    base::string16 index_name;
     {
       StringPiece slice(it->Value());
       if (!DecodeString(&slice, &index_name) || !slice.empty())
@@ -1553,7 +1554,7 @@ bool IndexedDBBackingStore::CreateIndex(
     int64 database_id,
     int64 object_store_id,
     int64 index_id,
-    const string16& name,
+    const base::string16& name,
     const IndexedDBKeyPath& key_path,
     bool is_unique,
     bool is_multi_entry) {
diff --git a/content/browser/indexed_db/indexed_db_backing_store.h b/content/browser/indexed_db/indexed_db_backing_store.h
index 9ea71f1..00b15a3 100644
--- a/content/browser/indexed_db/indexed_db_backing_store.h
+++ b/content/browser/indexed_db/indexed_db_backing_store.h
@@ -69,19 +69,19 @@ class CONTENT_EXPORT IndexedDBBackingStore
       const GURL& origin_url,
       LevelDBFactory* factory);
 
-  virtual std::vector<string16> GetDatabaseNames();
-  virtual bool GetIDBDatabaseMetaData(const string16& name,
+  virtual std::vector<base::string16> GetDatabaseNames();
+  virtual bool GetIDBDatabaseMetaData(const base::string16& name,
                                       IndexedDBDatabaseMetadata* metadata,
                                       bool* success) WARN_UNUSED_RESULT;
-  virtual bool CreateIDBDatabaseMetaData(const string16& name,
-                                         const string16& version,
+  virtual bool CreateIDBDatabaseMetaData(const base::string16& name,
+                                         const base::string16& version,
                                          int64 int_version,
                                          int64* row_id);
   virtual bool UpdateIDBDatabaseIntVersion(
       IndexedDBBackingStore::Transaction* transaction,
       int64 row_id,
       int64 int_version);
-  virtual bool DeleteDatabase(const string16& name);
+  virtual bool DeleteDatabase(const base::string16& name);
 
   bool GetObjectStores(int64 database_id,
                        IndexedDBDatabaseMetadata::ObjectStoreMap* map)
@@ -90,7 +90,7 @@ class CONTENT_EXPORT IndexedDBBackingStore
       IndexedDBBackingStore::Transaction* transaction,
       int64 database_id,
       int64 object_store_id,
-      const string16& name,
+      const base::string16& name,
       const IndexedDBKeyPath& key_path,
       bool auto_increment);
   virtual bool DeleteObjectStore(
@@ -160,7 +160,7 @@ class CONTENT_EXPORT IndexedDBBackingStore
                            int64 database_id,
                            int64 object_store_id,
                            int64 index_id,
-                           const string16& name,
+                           const base::string16& name,
                            const IndexedDBKeyPath& key_path,
                            bool is_unique,
                            bool is_multi_entry) WARN_UNUSED_RESULT;
diff --git a/content/browser/indexed_db/indexed_db_backing_store_unittest.cc b/content/browser/indexed_db/indexed_db_backing_store_unittest.cc
index 396189e..d3e8296 100644
--- a/content/browser/indexed_db/indexed_db_backing_store_unittest.cc
+++ b/content/browser/indexed_db/indexed_db_backing_store_unittest.cc
@@ -236,19 +236,19 @@ TEST_F(IndexedDBBackingStoreTest, InvalidIds) {
 }
 
 TEST_F(IndexedDBBackingStoreTest, CreateDatabase) {
-  const string16 database_name(ASCIIToUTF16("db1"));
+  const base::string16 database_name(ASCIIToUTF16("db1"));
   int64 database_id;
-  const string16 version(ASCIIToUTF16("old_string_version"));
+  const base::string16 version(ASCIIToUTF16("old_string_version"));
   const int64 int_version = 9;
 
   const int64 object_store_id = 99;
-  const string16 object_store_name(ASCIIToUTF16("object_store1"));
+  const base::string16 object_store_name(ASCIIToUTF16("object_store1"));
   const bool auto_increment = true;
   const IndexedDBKeyPath object_store_key_path(
       ASCIIToUTF16("object_store_key"));
 
   const int64 index_id = 999;
-  const string16 index_name(ASCIIToUTF16("index1"));
+  const base::string16 index_name(ASCIIToUTF16("index1"));
   const bool unique = true;
   const bool multi_entry = true;
   const IndexedDBKeyPath index_key_path(ASCIIToUTF16("index_key"));
diff --git a/content/browser/indexed_db/indexed_db_browsertest.cc b/content/browser/indexed_db/indexed_db_browsertest.cc
index 687ce48..74b81b6 100644
--- a/content/browser/indexed_db/indexed_db_browsertest.cc
+++ b/content/browser/indexed_db/indexed_db_browsertest.cc
@@ -66,7 +66,7 @@ class IndexedDBBrowserTest : public ContentBrowserTest {
     if (hash)
       url = GURL(url.spec() + hash);
 
-    string16 expected_title16(ASCIIToUTF16(expected_string));
+    base::string16 expected_title16(ASCIIToUTF16(expected_string));
     TitleWatcher title_watcher(shell->web_contents(), expected_title16);
     NavigateToURL(shell, url);
     EXPECT_EQ(expected_title16, title_watcher.WaitAndGetTitle());
@@ -399,7 +399,7 @@ IN_PROC_BROWSER_TEST_F(IndexedDBBrowserTest, ConnectionsClosedOnTabClose) {
   NavigateAndWaitForTitle(new_shell, "version_change_blocked.html", "#tab2",
                           "setVersion(3) blocked");
 
-  string16 expected_title16(ASCIIToUTF16("setVersion(3) complete"));
+  base::string16 expected_title16(ASCIIToUTF16("setVersion(3) complete"));
   TitleWatcher title_watcher(new_shell->web_contents(), expected_title16);
 
   base::KillProcess(
@@ -421,7 +421,7 @@ IN_PROC_BROWSER_TEST_F(IndexedDBBrowserTest, ForceCloseEventTest) {
                  GetContext(),
                  GURL("file:///")));
 
-  string16 expected_title16(ASCIIToUTF16("connection closed"));
+  base::string16 expected_title16(ASCIIToUTF16("connection closed"));
   TitleWatcher title_watcher(shell()->web_contents(), expected_title16);
   EXPECT_EQ(expected_title16, title_watcher.WaitAndGetTitle());
 }
diff --git a/content/browser/indexed_db/indexed_db_callbacks.cc b/content/browser/indexed_db/indexed_db_callbacks.cc
index 587b66f..755551c 100644
--- a/content/browser/indexed_db/indexed_db_callbacks.cc
+++ b/content/browser/indexed_db/indexed_db_callbacks.cc
@@ -71,7 +71,7 @@ void IndexedDBCallbacks::OnError(const IndexedDBDatabaseError& error) {
   dispatcher_host_ = NULL;
 }
 
-void IndexedDBCallbacks::OnSuccess(const std::vector<string16>& value) {
+void IndexedDBCallbacks::OnSuccess(const std::vector<base::string16>& value) {
   DCHECK(dispatcher_host_.get());
 
   DCHECK_EQ(kNoCursor, ipc_cursor_id_);
@@ -79,7 +79,7 @@ void IndexedDBCallbacks::OnSuccess(const std::vector<string16>& value) {
   DCHECK_EQ(kNoDatabase, ipc_database_id_);
   DCHECK_EQ(kNoDatabaseCallbacks, ipc_database_callbacks_id_);
 
-  std::vector<string16> list;
+  std::vector<base::string16> list;
   for (unsigned i = 0; i < value.size(); ++i)
     list.push_back(value[i]);
 
diff --git a/content/browser/indexed_db/indexed_db_callbacks.h b/content/browser/indexed_db/indexed_db_callbacks.h
index 1ea0c0b..048b563 100644
--- a/content/browser/indexed_db/indexed_db_callbacks.h
+++ b/content/browser/indexed_db/indexed_db_callbacks.h
@@ -51,7 +51,7 @@ class CONTENT_EXPORT IndexedDBCallbacks
   virtual void OnError(const IndexedDBDatabaseError& error);
 
   // IndexedDBFactory::GetDatabaseNames
-  virtual void OnSuccess(const std::vector<string16>& string);
+  virtual void OnSuccess(const std::vector<base::string16>& string);
 
   // IndexedDBFactory::Open / DeleteDatabase
   virtual void OnBlocked(int64 existing_version);
diff --git a/content/browser/indexed_db/indexed_db_database.cc b/content/browser/indexed_db/indexed_db_database.cc
index 8d63293..258b01e 100644
--- a/content/browser/indexed_db/indexed_db_database.cc
+++ b/content/browser/indexed_db/indexed_db_database.cc
@@ -108,7 +108,7 @@ class IndexedDBDatabase::PendingDeleteCall {
 };
 
 scoped_refptr<IndexedDBDatabase> IndexedDBDatabase::Create(
-    const string16& name,
+    const base::string16& name,
     IndexedDBBackingStore* backing_store,
     IndexedDBFactory* factory,
     const Identifier& unique_identifier) {
@@ -128,7 +128,7 @@ bool Contains(const T& container, const U& item) {
 }
 }
 
-IndexedDBDatabase::IndexedDBDatabase(const string16& name,
+IndexedDBDatabase::IndexedDBDatabase(const base::string16& name,
                                      IndexedDBBackingStore* backing_store,
                                      IndexedDBFactory* factory,
                                      const Identifier& unique_identifier)
@@ -273,7 +273,7 @@ bool IndexedDBDatabase::ValidateObjectStoreIdAndNewIndexId(
 
 void IndexedDBDatabase::CreateObjectStore(int64 transaction_id,
                                           int64 object_store_id,
-                                          const string16& name,
+                                          const base::string16& name,
                                           const IndexedDBKeyPath& key_path,
                                           bool auto_increment) {
   IDB_TRACE("IndexedDBDatabase::CreateObjectStore");
@@ -351,7 +351,7 @@ void IndexedDBDatabase::DeleteObjectStore(int64 transaction_id,
 void IndexedDBDatabase::CreateIndex(int64 transaction_id,
                                     int64 object_store_id,
                                     int64 index_id,
-                                    const string16& name,
+                                    const base::string16& name,
                                     const IndexedDBKeyPath& key_path,
                                     bool unique,
                                     bool multi_entry) {
@@ -392,8 +392,9 @@ void IndexedDBDatabase::CreateIndexOperation(
                                    index_metadata.key_path,
                                    index_metadata.unique,
                                    index_metadata.multi_entry)) {
-    string16 error_string = ASCIIToUTF16("Internal error creating index '") +
-                            index_metadata.name + ASCIIToUTF16("'.");
+    base::string16 error_string =
+        ASCIIToUTF16("Internal error creating index '") +
+        index_metadata.name + ASCIIToUTF16("'.");
     transaction->Abort(IndexedDBDatabaseError(
         blink::WebIDBDatabaseExceptionUnknownError, error_string));
     return;
@@ -446,8 +447,9 @@ void IndexedDBDatabase::DeleteIndexOperation(
                                         object_store_id,
                                         index_metadata.id);
   if (!ok) {
-    string16 error_string = ASCIIToUTF16("Internal error deleting index '") +
-                            index_metadata.name + ASCIIToUTF16("'.");
+    base::string16 error_string =
+        ASCIIToUTF16("Internal error deleting index '") +
+        index_metadata.name + ASCIIToUTF16("'.");
     transaction->Abort(IndexedDBDatabaseError(
         blink::WebIDBDatabaseExceptionUnknownError, error_string));
   }
@@ -791,7 +793,7 @@ void IndexedDBDatabase::PutOperation(scoped_ptr<PutOperationParams> params,
   }
 
   ScopedVector<IndexWriter> index_writers;
-  string16 error_message;
+  base::string16 error_message;
   bool obeys_constraints = false;
   bool backing_store_success = MakeIndexWriters(transaction,
                                                 backing_store_.get(),
@@ -897,7 +899,7 @@ void IndexedDBDatabase::SetIndexKeys(int64 transaction_id,
   }
 
   ScopedVector<IndexWriter> index_writers;
-  string16 error_message;
+  base::string16 error_message;
   bool obeys_constraints = false;
   DCHECK(metadata_.object_stores.find(object_store_id) !=
          metadata_.object_stores.end());
@@ -1219,7 +1221,7 @@ void IndexedDBDatabase::DeleteObjectStoreOperation(
                                         transaction->database()->id(),
                                         object_store_metadata.id);
   if (!ok) {
-    string16 error_string =
+    base::string16 error_string =
         ASCIIToUTF16("Internal error deleting object store '") +
         object_store_metadata.name + ASCIIToUTF16("'.");
     transaction->Abort(IndexedDBDatabaseError(
@@ -1449,7 +1451,7 @@ void IndexedDBDatabase::OpenConnection(
       DCHECK_EQ(IndexedDBDatabaseMetadata::NO_INT_VERSION,
                 metadata_.int_version);
     } else {
-      string16 message;
+      base::string16 message;
       if (version == IndexedDBDatabaseMetadata::NO_INT_VERSION)
         message = ASCIIToUTF16(
             "Internal error opening database with no version specified.");
@@ -1714,7 +1716,7 @@ void IndexedDBDatabase::DeleteObjectStoreAbortOperation(
 }
 
 void IndexedDBDatabase::VersionChangeAbortOperation(
-    const string16& previous_version,
+    const base::string16& previous_version,
     int64 previous_int_version,
     IndexedDBTransaction* transaction) {
   IDB_TRACE("IndexedDBDatabase::VersionChangeAbortOperation");
diff --git a/content/browser/indexed_db/indexed_db_database.h b/content/browser/indexed_db/indexed_db_database.h
index fa730b0..b9b4dac 100644
--- a/content/browser/indexed_db/indexed_db_database.h
+++ b/content/browser/indexed_db/indexed_db_database.h
@@ -52,7 +52,7 @@ class CONTENT_EXPORT IndexedDBDatabase
   static const int64 kMinimumIndexId = 30;
 
   static scoped_refptr<IndexedDBDatabase> Create(
-      const string16& name,
+      const base::string16& name,
       IndexedDBBackingStore* backing_store,
       IndexedDBFactory* factory,
       const Identifier& unique_identifier);
@@ -88,7 +88,7 @@ class CONTENT_EXPORT IndexedDBDatabase
 
   void CreateObjectStore(int64 transaction_id,
                          int64 object_store_id,
-                         const string16& name,
+                         const base::string16& name,
                          const IndexedDBKeyPath& key_path,
                          bool auto_increment);
   void DeleteObjectStore(int64 transaction_id, int64 object_store_id);
@@ -105,7 +105,7 @@ class CONTENT_EXPORT IndexedDBDatabase
   void CreateIndex(int64 transaction_id,
                    int64 object_store_id,
                    int64 index_id,
-                   const string16& name,
+                   const base::string16& name,
                    const IndexedDBKeyPath& key_path,
                    bool unique,
                    bool multi_entry);
@@ -198,7 +198,7 @@ class CONTENT_EXPORT IndexedDBDatabase
                               blink::WebIDBDataLoss data_loss,
                               std::string data_loss_message,
                               IndexedDBTransaction* transaction);
-  void VersionChangeAbortOperation(const string16& previous_version,
+  void VersionChangeAbortOperation(const base::string16& previous_version,
                                    int64 previous_int_version,
                                    IndexedDBTransaction* transaction);
   void CreateIndexOperation(int64 object_store_id,
@@ -243,7 +243,7 @@ class CONTENT_EXPORT IndexedDBDatabase
  private:
   friend class base::RefCounted<IndexedDBDatabase>;
 
-  IndexedDBDatabase(const string16& name,
+  IndexedDBDatabase(const base::string16& name,
                     IndexedDBBackingStore* backing_store,
                     IndexedDBFactory* factory,
                     const Identifier& unique_identifier);
diff --git a/content/browser/indexed_db/indexed_db_database_error.h b/content/browser/indexed_db/indexed_db_database_error.h
index 297bec7..1a4f449 100644
--- a/content/browser/indexed_db/indexed_db_database_error.h
+++ b/content/browser/indexed_db/indexed_db_database_error.h
@@ -17,16 +17,16 @@ class IndexedDBDatabaseError {
       : code_(code) {}
   IndexedDBDatabaseError(uint16 code, const char* message)
       : code_(code), message_(ASCIIToUTF16(message)) {}
-  IndexedDBDatabaseError(uint16 code, const string16& message)
+  IndexedDBDatabaseError(uint16 code, const base::string16& message)
       : code_(code), message_(message) {}
   ~IndexedDBDatabaseError() {}
 
   uint16 code() const { return code_; }
-  const string16& message() const { return message_; }
+  const base::string16& message() const { return message_; }
 
  private:
   const uint16 code_;
-  const string16 message_;
+  const base::string16 message_;
 };
 
 }  // namespace content
diff --git a/content/browser/indexed_db/indexed_db_factory.cc b/content/browser/indexed_db/indexed_db_factory.cc
index 2cfef62..bd0c0ad 100644
--- a/content/browser/indexed_db/indexed_db_factory.cc
+++ b/content/browser/indexed_db/indexed_db_factory.cc
@@ -130,7 +130,7 @@ void IndexedDBFactory::GetDatabaseNames(
 }
 
 void IndexedDBFactory::DeleteDatabase(
-    const string16& name,
+    const base::string16& name,
     scoped_refptr<IndexedDBCallbacks> callbacks,
     const GURL& origin_url,
     const base::FilePath& data_directory) {
@@ -233,7 +233,7 @@ scoped_refptr<IndexedDBBackingStore> IndexedDBFactory::OpenBackingStore(
 }
 
 void IndexedDBFactory::Open(
-    const string16& name,
+    const base::string16& name,
     int64 version,
     int64 transaction_id,
     scoped_refptr<IndexedDBCallbacks> callbacks,
diff --git a/content/browser/indexed_db/indexed_db_factory.h b/content/browser/indexed_db/indexed_db_factory.h
index b143853..74168d6 100644
--- a/content/browser/indexed_db/indexed_db_factory.h
+++ b/content/browser/indexed_db/indexed_db_factory.h
@@ -36,7 +36,7 @@ class CONTENT_EXPORT IndexedDBFactory
   void GetDatabaseNames(scoped_refptr<IndexedDBCallbacks> callbacks,
                         const GURL& origin_url,
                         const base::FilePath& data_directory);
-  void Open(const string16& name,
+  void Open(const base::string16& name,
             int64 version,
             int64 transaction_id,
             scoped_refptr<IndexedDBCallbacks> callbacks,
@@ -44,7 +44,7 @@ class CONTENT_EXPORT IndexedDBFactory
             const GURL& origin_url,
             const base::FilePath& data_directory);
 
-  void DeleteDatabase(const string16& name,
+  void DeleteDatabase(const base::string16& name,
                       scoped_refptr<IndexedDBCallbacks> callbacks,
                       const GURL& origin_url,
                       const base::FilePath& data_directory);
diff --git a/content/browser/indexed_db/indexed_db_factory_unittest.cc b/content/browser/indexed_db/indexed_db_factory_unittest.cc
index 859c2b7..9afa9e7 100644
--- a/content/browser/indexed_db/indexed_db_factory_unittest.cc
+++ b/content/browser/indexed_db/indexed_db_factory_unittest.cc
@@ -217,7 +217,7 @@ TEST_F(IndexedDBFactoryTest, QuotaErrorOnDiskFull) {
       new LookingForQuotaErrorMockCallbacks;
   scoped_refptr<IndexedDBDatabaseCallbacks> dummy_database_callbacks =
       new IndexedDBDatabaseCallbacks(NULL, 0, 0);
-  const string16 name(ASCIIToUTF16("name"));
+  const base::string16 name(ASCIIToUTF16("name"));
   factory->Open(name,
                 1, /* version */
                 2, /* transaction_id */
diff --git a/content/browser/indexed_db/indexed_db_fake_backing_store.cc b/content/browser/indexed_db/indexed_db_fake_backing_store.cc
index 8766162..3825982 100644
--- a/content/browser/indexed_db/indexed_db_fake_backing_store.cc
+++ b/content/browser/indexed_db/indexed_db_fake_backing_store.cc
@@ -10,19 +10,19 @@ namespace content {
 
 IndexedDBFakeBackingStore::~IndexedDBFakeBackingStore() {}
 
-std::vector<string16> IndexedDBFakeBackingStore::GetDatabaseNames() {
-  return std::vector<string16>();
+std::vector<base::string16> IndexedDBFakeBackingStore::GetDatabaseNames() {
+  return std::vector<base::string16>();
 }
 bool IndexedDBFakeBackingStore::GetIDBDatabaseMetaData(
-    const string16& name,
+    const base::string16& name,
     IndexedDBDatabaseMetadata*,
     bool* found) {
   return true;
 }
 
 bool IndexedDBFakeBackingStore::CreateIDBDatabaseMetaData(
-    const string16& name,
-    const string16& version,
+    const base::string16& name,
+    const base::string16& version,
     int64 int_version,
     int64* row_id) {
   return true;
@@ -32,14 +32,14 @@ bool IndexedDBFakeBackingStore::UpdateIDBDatabaseIntVersion(Transaction*,
                                                             int64 version) {
   return false;
 }
-bool IndexedDBFakeBackingStore::DeleteDatabase(const string16& name) {
+bool IndexedDBFakeBackingStore::DeleteDatabase(const base::string16& name) {
   return true;
 }
 
 bool IndexedDBFakeBackingStore::CreateObjectStore(Transaction*,
                                                   int64 database_id,
                                                   int64 object_store_id,
-                                                  const string16& name,
+                                                  const base::string16& name,
                                                   const IndexedDBKeyPath&,
                                                   bool auto_increment) {
   return false;
@@ -85,7 +85,7 @@ bool IndexedDBFakeBackingStore::CreateIndex(Transaction*,
                                             int64 database_id,
                                             int64 object_store_id,
                                             int64 index_id,
-                                            const string16& name,
+                                            const base::string16& name,
                                             const IndexedDBKeyPath&,
                                             bool is_unique,
                                             bool is_multi_entry) {
diff --git a/content/browser/indexed_db/indexed_db_fake_backing_store.h b/content/browser/indexed_db/indexed_db_fake_backing_store.h
index 07b63de..93d047c 100644
--- a/content/browser/indexed_db/indexed_db_fake_backing_store.h
+++ b/content/browser/indexed_db/indexed_db_fake_backing_store.h
@@ -17,23 +17,23 @@ class IndexedDBFakeBackingStore : public IndexedDBBackingStore {
       : IndexedDBBackingStore(GURL("http://localhost:81"),
                               scoped_ptr<LevelDBDatabase>(),
                               scoped_ptr<LevelDBComparator>()) {}
-  virtual std::vector<string16> GetDatabaseNames() OVERRIDE;
-  virtual bool GetIDBDatabaseMetaData(const string16& name,
+  virtual std::vector<base::string16> GetDatabaseNames() OVERRIDE;
+  virtual bool GetIDBDatabaseMetaData(const base::string16& name,
                                       IndexedDBDatabaseMetadata*,
                                       bool* found) OVERRIDE;
-  virtual bool CreateIDBDatabaseMetaData(const string16& name,
-                                         const string16& version,
+  virtual bool CreateIDBDatabaseMetaData(const base::string16& name,
+                                         const base::string16& version,
                                          int64 int_version,
                                          int64* row_id) OVERRIDE;
   virtual bool UpdateIDBDatabaseIntVersion(Transaction*,
                                            int64 row_id,
                                            int64 version) OVERRIDE;
-  virtual bool DeleteDatabase(const string16& name) OVERRIDE;
+  virtual bool DeleteDatabase(const base::string16& name) OVERRIDE;
 
   virtual bool CreateObjectStore(Transaction*,
                                  int64 database_id,
                                  int64 object_store_id,
-                                 const string16& name,
+                                 const base::string16& name,
                                  const IndexedDBKeyPath&,
                                  bool auto_increment) OVERRIDE;
 
@@ -65,7 +65,7 @@ class IndexedDBFakeBackingStore : public IndexedDBBackingStore {
                            int64 database_id,
                            int64 object_store_id,
                            int64 index_id,
-                           const string16& name,
+                           const base::string16& name,
                            const IndexedDBKeyPath&,
                            bool is_unique,
                            bool is_multi_entry) OVERRIDE;
diff --git a/content/browser/indexed_db/indexed_db_index_writer.cc b/content/browser/indexed_db/indexed_db_index_writer.cc
index 3b36cad..1c2ac0a 100644
--- a/content/browser/indexed_db/indexed_db_index_writer.cc
+++ b/content/browser/indexed_db/indexed_db_index_writer.cc
@@ -34,7 +34,7 @@ bool IndexWriter::VerifyIndexKeys(
     int64 index_id,
     bool* can_add_keys,
     const IndexedDBKey& primary_key,
-    string16* error_message) const {
+    base::string16* error_message) const {
   *can_add_keys = false;
   for (size_t i = 0; i < index_keys_.size(); ++i) {
     bool ok = AddingKeyAllowed(backing_store,
@@ -122,7 +122,7 @@ bool MakeIndexWriters(
     const std::vector<int64>& index_ids,
     const std::vector<IndexedDBDatabase::IndexKeys>& index_keys,
     ScopedVector<IndexWriter>* index_writers,
-    string16* error_message,
+    base::string16* error_message,
     bool* completed) {
   DCHECK_EQ(index_ids.size(), index_keys.size());
   *completed = false;
diff --git a/content/browser/indexed_db/indexed_db_index_writer.h b/content/browser/indexed_db/indexed_db_index_writer.h
index 2ea1c98..8a2cdad 100644
--- a/content/browser/indexed_db/indexed_db_index_writer.h
+++ b/content/browser/indexed_db/indexed_db_index_writer.h
@@ -34,7 +34,7 @@ class IndexWriter {
                        int64 index_id,
                        bool* can_add_keys,
                        const IndexedDBKey& primary_key,
-                       string16* error_message) const WARN_UNUSED_RESULT;
+                       base::string16* error_message) const WARN_UNUSED_RESULT;
 
   void WriteIndexKeys(const IndexedDBBackingStore::RecordIdentifier& record,
                       IndexedDBBackingStore* store,
@@ -68,7 +68,7 @@ bool MakeIndexWriters(
     const std::vector<int64>& index_ids,
     const std::vector<IndexedDBDatabase::IndexKeys>& index_keys,
     ScopedVector<IndexWriter>* index_writers,
-    string16* error_message,
+    base::string16* error_message,
     bool* completed) WARN_UNUSED_RESULT;
 
 }  // namespace content
diff --git a/content/browser/indexed_db/indexed_db_leveldb_coding.cc b/content/browser/indexed_db/indexed_db_leveldb_coding.cc
index dd3964a..fad767c 100644
--- a/content/browser/indexed_db/indexed_db_leveldb_coding.cc
+++ b/content/browser/indexed_db/indexed_db_leveldb_coding.cc
@@ -257,7 +257,7 @@ void EncodeVarInt(int64 value, std::string* into) {
   } while (n);
 }
 
-void EncodeString(const string16& value, std::string* into) {
+void EncodeString(const base::string16& value, std::string* into) {
   if (value.empty())
     return;
   // Backing store is UTF-16BE, convert from host endianness.
@@ -277,7 +277,7 @@ void EncodeBinary(const std::string& value, std::string* into) {
   DCHECK(into->size() >= value.size());
 }
 
-void EncodeStringWithLength(const string16& value, std::string* into) {
+void EncodeStringWithLength(const base::string16& value, std::string* into) {
   EncodeVarInt(value.length(), into);
   EncodeString(value, into);
 }
@@ -355,7 +355,7 @@ void EncodeIDBKeyPath(const IndexedDBKeyPath& value, std::string* into) {
       break;
     }
     case WebIDBKeyPathTypeArray: {
-      const std::vector<string16>& array = value.array();
+      const std::vector<base::string16>& array = value.array();
       size_t count = array.size();
       EncodeVarInt(count, into);
       for (size_t i = 0; i < count; ++i) {
@@ -421,7 +421,7 @@ bool DecodeVarInt(StringPiece* slice, int64* value) {
   return true;
 }
 
-bool DecodeString(StringPiece* slice, string16* value) {
+bool DecodeString(StringPiece* slice, base::string16* value) {
   if (slice->empty()) {
     value->clear();
     return true;
@@ -430,7 +430,7 @@ bool DecodeString(StringPiece* slice, string16* value) {
   // Backing store is UTF-16BE, convert to host endianness.
   DCHECK(!(slice->size() % sizeof(char16)));
   size_t length = slice->size() / sizeof(char16);
-  string16 decoded;
+  base::string16 decoded;
   decoded.reserve(length);
   const char16* encoded = reinterpret_cast<const char16*>(slice->begin());
   for (unsigned i = 0; i < length; ++i)
@@ -441,7 +441,7 @@ bool DecodeString(StringPiece* slice, string16* value) {
   return true;
 }
 
-bool DecodeStringWithLength(StringPiece* slice, string16* value) {
+bool DecodeStringWithLength(StringPiece* slice, base::string16* value) {
   if (slice->empty())
     return false;
 
@@ -510,7 +510,7 @@ bool DecodeIDBKey(StringPiece* slice, scoped_ptr<IndexedDBKey>* value) {
       return true;
     }
     case kIndexedDBKeyStringTypeByte: {
-      string16 s;
+      base::string16 s;
       if (!DecodeStringWithLength(slice, &s))
         return false;
       *value = make_scoped_ptr(new IndexedDBKey(s));
@@ -551,7 +551,7 @@ bool DecodeIDBKeyPath(StringPiece* slice, IndexedDBKeyPath* value) {
   // always written as typed.
   if (slice->size() < 3 || (*slice)[0] != kIndexedDBKeyPathTypeCodedByte1 ||
       (*slice)[1] != kIndexedDBKeyPathTypeCodedByte2) {
-    string16 s;
+    base::string16 s;
     if (!DecodeString(slice, &s))
       return false;
     *value = IndexedDBKeyPath(s);
@@ -569,7 +569,7 @@ bool DecodeIDBKeyPath(StringPiece* slice, IndexedDBKeyPath* value) {
       *value = IndexedDBKeyPath();
       return true;
     case WebIDBKeyPathTypeString: {
-      string16 string;
+      base::string16 string;
       if (!DecodeStringWithLength(slice, &string))
         return false;
       DCHECK(slice->empty());
@@ -577,13 +577,13 @@ bool DecodeIDBKeyPath(StringPiece* slice, IndexedDBKeyPath* value) {
       return true;
     }
     case WebIDBKeyPathTypeArray: {
-      std::vector<string16> array;
+      std::vector<base::string16> array;
       int64 count;
       if (!DecodeVarInt(slice, &count))
         return false;
       DCHECK_GE(count, 0);
       while (count--) {
-        string16 string;
+        base::string16 string;
         if (!DecodeStringWithLength(slice, &string))
           return false;
         array.push_back(string);
@@ -1324,7 +1324,7 @@ bool DatabaseNameKey::Decode(StringPiece* slice, DatabaseNameKey* result) {
 }
 
 std::string DatabaseNameKey::Encode(const std::string& origin_identifier,
-                                    const string16& database_name) {
+                                    const base::string16& database_name) {
   std::string ret = KeyPrefix::EncodeEmpty();
   ret.push_back(kDatabaseNameTypeByte);
   EncodeStringWithLength(base::ASCIIToUTF16(origin_identifier), &ret);
@@ -1334,7 +1334,7 @@ std::string DatabaseNameKey::Encode(const std::string& origin_identifier,
 
 std::string DatabaseNameKey::EncodeMinKeyForOrigin(
     const std::string& origin_identifier) {
-  return Encode(origin_identifier, string16());
+  return Encode(origin_identifier, base::string16());
 }
 
 std::string DatabaseNameKey::EncodeStopKeyForOrigin(
@@ -1604,8 +1604,9 @@ bool ObjectStoreNamesKey::Decode(StringPiece* slice,
   return true;
 }
 
-std::string ObjectStoreNamesKey::Encode(int64 database_id,
-                                        const string16& object_store_name) {
+std::string ObjectStoreNamesKey::Encode(
+    int64 database_id,
+    const base::string16& object_store_name) {
   KeyPrefix prefix(database_id);
   std::string ret = prefix.Encode();
   ret.push_back(kObjectStoreNamesTypeByte);
@@ -1641,7 +1642,7 @@ bool IndexNamesKey::Decode(StringPiece* slice, IndexNamesKey* result) {
 
 std::string IndexNamesKey::Encode(int64 database_id,
                                   int64 object_store_id,
-                                  const string16& index_name) {
+                                  const base::string16& index_name) {
   KeyPrefix prefix(database_id);
   std::string ret = prefix.Encode();
   ret.push_back(kIndexNamesKeyTypeByte);
diff --git a/content/browser/indexed_db/indexed_db_leveldb_coding.h b/content/browser/indexed_db/indexed_db_leveldb_coding.h
index 8d0c780..d369af0 100644
--- a/content/browser/indexed_db/indexed_db_leveldb_coding.h
+++ b/content/browser/indexed_db/indexed_db_leveldb_coding.h
@@ -27,8 +27,9 @@ CONTENT_EXPORT void EncodeByte(unsigned char value, std::string* into);
 CONTENT_EXPORT void EncodeBool(bool value, std::string* into);
 CONTENT_EXPORT void EncodeInt(int64 value, std::string* into);
 CONTENT_EXPORT void EncodeVarInt(int64 value, std::string* into);
-CONTENT_EXPORT void EncodeString(const string16& value, std::string* into);
-CONTENT_EXPORT void EncodeStringWithLength(const string16& value,
+CONTENT_EXPORT void EncodeString(const base::string16& value,
+                                 std::string* into);
+CONTENT_EXPORT void EncodeStringWithLength(const base::string16& value,
                                            std::string* into);
 CONTENT_EXPORT void EncodeBinary(const std::string& value, std::string* into);
 CONTENT_EXPORT void EncodeDouble(double value, std::string* into);
@@ -45,10 +46,10 @@ CONTENT_EXPORT WARN_UNUSED_RESULT bool DecodeInt(base::StringPiece* slice,
 CONTENT_EXPORT WARN_UNUSED_RESULT bool DecodeVarInt(base::StringPiece* slice,
                                                     int64* value);
 CONTENT_EXPORT WARN_UNUSED_RESULT bool DecodeString(base::StringPiece* slice,
-                                                    string16* value);
+                                                    base::string16* value);
 CONTENT_EXPORT WARN_UNUSED_RESULT bool DecodeStringWithLength(
     base::StringPiece* slice,
-    string16* value);
+    base::string16* value);
 CONTENT_EXPORT WARN_UNUSED_RESULT bool DecodeBinary(base::StringPiece* slice,
                                                     std::string* value);
 CONTENT_EXPORT WARN_UNUSED_RESULT bool DecodeDouble(base::StringPiece* slice,
@@ -188,18 +189,19 @@ class DatabaseNameKey {
  public:
   static bool Decode(base::StringPiece* slice, DatabaseNameKey* result);
   CONTENT_EXPORT static std::string Encode(const std::string& origin_identifier,
-                                           const string16& database_name);
+                                           const base::string16& database_name);
   static std::string EncodeMinKeyForOrigin(
       const std::string& origin_identifier);
   static std::string EncodeStopKeyForOrigin(
       const std::string& origin_identifier);
-  string16 origin() const { return origin_; }
-  string16 database_name() const { return database_name_; }
+  base::string16 origin() const { return origin_; }
+  base::string16 database_name() const { return database_name_; }
   int Compare(const DatabaseNameKey& other);
 
  private:
-  string16 origin_;  // TODO(jsbell): Store encoded strings, or just pointers.
-  string16 database_name_;
+  base::string16 origin_;  // TODO(jsbell): Store encoded strings, or just
+                           // pointers.
+  base::string16 database_name_;
 };
 
 class DatabaseMetaDataKey {
@@ -315,14 +317,15 @@ class ObjectStoreNamesKey {
   // because a mapping is kept in the IndexedDBDatabase. Can the
   // mapping become unreliable?  Can we remove this?
   static bool Decode(base::StringPiece* slice, ObjectStoreNamesKey* result);
-  CONTENT_EXPORT static std::string Encode(int64 database_id,
-                                           const string16& object_store_name);
+  CONTENT_EXPORT static std::string Encode(
+      int64 database_id,
+      const base::string16& object_store_name);
   int Compare(const ObjectStoreNamesKey& other);
-  string16 object_store_name() const { return object_store_name_; }
+  base::string16 object_store_name() const { return object_store_name_; }
 
  private:
   // TODO(jsbell): Store the encoded string, or just pointers to it.
-  string16 object_store_name_;
+  base::string16 object_store_name_;
 };
 
 class IndexNamesKey {
@@ -333,13 +336,13 @@ class IndexNamesKey {
   static bool Decode(base::StringPiece* slice, IndexNamesKey* result);
   CONTENT_EXPORT static std::string Encode(int64 database_id,
                                            int64 object_store_id,
-                                           const string16& index_name);
+                                           const base::string16& index_name);
   int Compare(const IndexNamesKey& other);
-  string16 index_name() const { return index_name_; }
+  base::string16 index_name() const { return index_name_; }
 
  private:
   int64 object_store_id_;
-  string16 index_name_;
+  base::string16 index_name_;
 };
 
 class ObjectStoreDataKey {
diff --git a/content/browser/indexed_db/indexed_db_leveldb_coding_unittest.cc b/content/browser/indexed_db/indexed_db_leveldb_coding_unittest.cc
index 6d6ab0b..e968142 100644
--- a/content/browser/indexed_db/indexed_db_leveldb_coding_unittest.cc
+++ b/content/browser/indexed_db/indexed_db_leveldb_coding_unittest.cc
@@ -304,7 +304,7 @@ TEST(IndexedDBLevelDBCodingTest, DecodeVarInt) {
   }
 }
 
-static std::string WrappedEncodeString(string16 value) {
+static std::string WrappedEncodeString(base::string16 value) {
   std::string buffer;
   EncodeString(value, &buffer);
   return buffer;
@@ -321,24 +321,24 @@ TEST(IndexedDBLevelDBCodingTest, EncodeString) {
   EXPECT_EQ(static_cast<size_t>(6),
             WrappedEncodeString(ASCIIToUTF16("foo")).size());
   EXPECT_EQ(static_cast<size_t>(6),
-            WrappedEncodeString(string16(test_string_a)).size());
+            WrappedEncodeString(base::string16(test_string_a)).size());
   EXPECT_EQ(static_cast<size_t>(4),
-            WrappedEncodeString(string16(test_string_b)).size());
+            WrappedEncodeString(base::string16(test_string_b)).size());
 }
 
 TEST(IndexedDBLevelDBCodingTest, DecodeString) {
   const char16 test_string_a[] = {'f', 'o', 'o', '\0'};
   const char16 test_string_b[] = {0xdead, 0xbeef, '\0'};
 
-  std::vector<string16> test_cases;
-  test_cases.push_back(string16());
+  std::vector<base::string16> test_cases;
+  test_cases.push_back(base::string16());
   test_cases.push_back(ASCIIToUTF16("a"));
   test_cases.push_back(ASCIIToUTF16("foo"));
   test_cases.push_back(test_string_a);
   test_cases.push_back(test_string_b);
 
   for (size_t i = 0; i < test_cases.size(); ++i) {
-    const string16& test_case = test_cases[i];
+    const base::string16& test_case = test_cases[i];
     std::string v = WrappedEncodeString(test_case);
 
     StringPiece slice;
@@ -346,7 +346,7 @@ TEST(IndexedDBLevelDBCodingTest, DecodeString) {
       slice = StringPiece(&*v.begin(), v.size());
     }
 
-    string16 result;
+    base::string16 result;
     EXPECT_TRUE(DecodeString(&slice, &result));
     EXPECT_EQ(test_case, result);
     EXPECT_TRUE(slice.empty());
@@ -360,7 +360,7 @@ TEST(IndexedDBLevelDBCodingTest, DecodeString) {
   }
 }
 
-static std::string WrappedEncodeStringWithLength(string16 value) {
+static std::string WrappedEncodeStringWithLength(base::string16 value) {
   std::string buffer;
   EncodeStringWithLength(value, &buffer);
   return buffer;
@@ -371,13 +371,15 @@ TEST(IndexedDBLevelDBCodingTest, EncodeStringWithLength) {
   const char16 test_string_b[] = {0xdead, 0xbeef, '\0'};
 
   EXPECT_EQ(static_cast<size_t>(1),
-            WrappedEncodeStringWithLength(string16()).size());
+            WrappedEncodeStringWithLength(base::string16()).size());
   EXPECT_EQ(static_cast<size_t>(3),
             WrappedEncodeStringWithLength(ASCIIToUTF16("a")).size());
   EXPECT_EQ(static_cast<size_t>(7),
-            WrappedEncodeStringWithLength(string16(test_string_a)).size());
+            WrappedEncodeStringWithLength(
+                base::string16(test_string_a)).size());
   EXPECT_EQ(static_cast<size_t>(5),
-            WrappedEncodeStringWithLength(string16(test_string_b)).size());
+            WrappedEncodeStringWithLength(
+                base::string16(test_string_b)).size());
 }
 
 TEST(IndexedDBLevelDBCodingTest, DecodeStringWithLength) {
@@ -390,20 +392,20 @@ TEST(IndexedDBLevelDBCodingTest, DecodeStringWithLength) {
     long_string[i] = i;
   long_string[kLongStringLen] = 0;
 
-  std::vector<string16> test_cases;
+  std::vector<base::string16> test_cases;
   test_cases.push_back(ASCIIToUTF16(""));
   test_cases.push_back(ASCIIToUTF16("a"));
   test_cases.push_back(ASCIIToUTF16("foo"));
-  test_cases.push_back(string16(test_string_a));
-  test_cases.push_back(string16(test_string_b));
-  test_cases.push_back(string16(long_string));
+  test_cases.push_back(base::string16(test_string_a));
+  test_cases.push_back(base::string16(test_string_b));
+  test_cases.push_back(base::string16(long_string));
 
   for (size_t i = 0; i < test_cases.size(); ++i) {
-    string16 s = test_cases[i];
+    base::string16 s = test_cases[i];
     std::string v = WrappedEncodeStringWithLength(s);
     ASSERT_GT(v.size(), static_cast<size_t>(0));
     StringPiece slice(v);
-    string16 res;
+    base::string16 res;
     EXPECT_TRUE(DecodeStringWithLength(&slice, &res));
     EXPECT_EQ(s, res);
     EXPECT_TRUE(slice.empty());
@@ -444,23 +446,23 @@ TEST(IndexedDBLevelDBCodingTest, CompareEncodedStringsWithLength) {
   const char16 test_string_e[] = {0xd834, 0xdd1e, '\0'};
   const char16 test_string_f[] = {0xfffd, '\0'};
 
-  std::vector<string16> test_cases;
+  std::vector<base::string16> test_cases;
   test_cases.push_back(ASCIIToUTF16(""));
   test_cases.push_back(ASCIIToUTF16("a"));
   test_cases.push_back(ASCIIToUTF16("b"));
   test_cases.push_back(ASCIIToUTF16("baaa"));
   test_cases.push_back(ASCIIToUTF16("baab"));
   test_cases.push_back(ASCIIToUTF16("c"));
-  test_cases.push_back(string16(test_string_a));
-  test_cases.push_back(string16(test_string_b));
-  test_cases.push_back(string16(test_string_c));
-  test_cases.push_back(string16(test_string_d));
-  test_cases.push_back(string16(test_string_e));
-  test_cases.push_back(string16(test_string_f));
+  test_cases.push_back(base::string16(test_string_a));
+  test_cases.push_back(base::string16(test_string_b));
+  test_cases.push_back(base::string16(test_string_c));
+  test_cases.push_back(base::string16(test_string_d));
+  test_cases.push_back(base::string16(test_string_e));
+  test_cases.push_back(base::string16(test_string_f));
 
   for (size_t i = 0; i < test_cases.size() - 1; ++i) {
-    string16 a = test_cases[i];
-    string16 b = test_cases[i + 1];
+    base::string16 a = test_cases[i];
+    base::string16 b = test_cases[i + 1];
 
     EXPECT_LT(a.compare(b), 0);
     EXPECT_GT(b.compare(a), 0);
@@ -630,7 +632,7 @@ TEST(IndexedDBLevelDBCodingTest, EncodeDecodeIDBKeyPath) {
   }
 
   {
-    key_paths.push_back(IndexedDBKeyPath(string16()));
+    key_paths.push_back(IndexedDBKeyPath(base::string16()));
     char expected[] = {0, 0,  // Header
                        1,     // Type is string
                        0      // Length is 0
@@ -661,8 +663,8 @@ TEST(IndexedDBLevelDBCodingTest, EncodeDecodeIDBKeyPath) {
   }
 
   {
-    std::vector<string16> array;
-    array.push_back(string16());
+    std::vector<base::string16> array;
+    array.push_back(base::string16());
     array.push_back(ASCIIToUTF16("foo"));
     array.push_back(ASCIIToUTF16("foo.bar"));
 
@@ -700,7 +702,7 @@ TEST(IndexedDBLevelDBCodingTest, DecodeLegacyIDBKeyPath) {
   std::vector<std::string> encoded_paths;
 
   {
-    key_paths.push_back(IndexedDBKeyPath(string16()));
+    key_paths.push_back(IndexedDBKeyPath(base::string16()));
     encoded_paths.push_back(std::string());
   }
   {
diff --git a/content/browser/indexed_db/indexed_db_metadata.cc b/content/browser/indexed_db/indexed_db_metadata.cc
index 80d3142..47b7219 100644
--- a/content/browser/indexed_db/indexed_db_metadata.cc
+++ b/content/browser/indexed_db/indexed_db_metadata.cc
@@ -7,7 +7,7 @@
 namespace content {
 
 IndexedDBObjectStoreMetadata::IndexedDBObjectStoreMetadata(
-    const string16& name,
+    const base::string16& name,
     int64 id,
     const IndexedDBKeyPath& key_path,
     bool auto_increment,
@@ -23,11 +23,12 @@ IndexedDBObjectStoreMetadata::~IndexedDBObjectStoreMetadata() {}
 
 IndexedDBDatabaseMetadata::IndexedDBDatabaseMetadata()
     : int_version(NO_INT_VERSION) {}
-IndexedDBDatabaseMetadata::IndexedDBDatabaseMetadata(const string16& name,
-                                                     int64 id,
-                                                     const string16& version,
-                                                     int64 int_version,
-                                                     int64 max_object_store_id)
+IndexedDBDatabaseMetadata::IndexedDBDatabaseMetadata(
+    const base::string16& name,
+    int64 id,
+    const base::string16& version,
+    int64 int_version,
+    int64 max_object_store_id)
     : name(name),
       id(id),
       version(version),
diff --git a/content/browser/indexed_db/indexed_db_metadata.h b/content/browser/indexed_db/indexed_db_metadata.h
index 4e8562d..00970a6 100644
--- a/content/browser/indexed_db/indexed_db_metadata.h
+++ b/content/browser/indexed_db/indexed_db_metadata.h
@@ -15,7 +15,7 @@ namespace content {
 
 struct IndexedDBIndexMetadata {
   IndexedDBIndexMetadata() {}
-  IndexedDBIndexMetadata(const string16& name,
+  IndexedDBIndexMetadata(const base::string16& name,
                          int64 id,
                          const IndexedDBKeyPath& key_path,
                          bool unique,
@@ -25,7 +25,7 @@ struct IndexedDBIndexMetadata {
         key_path(key_path),
         unique(unique),
         multi_entry(multi_entry) {}
-  string16 name;
+  base::string16 name;
   int64 id;
   IndexedDBKeyPath key_path;
   bool unique;
@@ -36,13 +36,13 @@ struct IndexedDBIndexMetadata {
 
 struct CONTENT_EXPORT IndexedDBObjectStoreMetadata {
   IndexedDBObjectStoreMetadata();
-  IndexedDBObjectStoreMetadata(const string16& name,
+  IndexedDBObjectStoreMetadata(const base::string16& name,
                                int64 id,
                                const IndexedDBKeyPath& key_path,
                                bool auto_increment,
                                int64 max_index_id);
   ~IndexedDBObjectStoreMetadata();
-  string16 name;
+  base::string16 name;
   int64 id;
   IndexedDBKeyPath key_path;
   bool auto_increment;
@@ -64,16 +64,16 @@ struct CONTENT_EXPORT IndexedDBDatabaseMetadata {
   typedef std::map<int64, IndexedDBObjectStoreMetadata> ObjectStoreMap;
 
   IndexedDBDatabaseMetadata();
-  IndexedDBDatabaseMetadata(const string16& name,
+  IndexedDBDatabaseMetadata(const base::string16& name,
                             int64 id,
-                            const string16& version,
+                            const base::string16& version,
                             int64 int_version,
                             int64 max_object_store_id);
   ~IndexedDBDatabaseMetadata();
 
-  string16 name;
+  base::string16 name;
   int64 id;
-  string16 version;
+  base::string16 version;
   int64 int_version;
   int64 max_object_store_id;
 
diff --git a/content/browser/loader/resource_dispatcher_host_browsertest.cc b/content/browser/loader/resource_dispatcher_host_browsertest.cc
index 0a763fe..011c975 100644
--- a/content/browser/loader/resource_dispatcher_host_browsertest.cc
+++ b/content/browser/loader/resource_dispatcher_host_browsertest.cc
@@ -59,13 +59,13 @@ class ResourceDispatcherHostBrowserTest : public ContentBrowserTest,
 
   void CheckTitleTest(const GURL& url,
                       const std::string& expected_title) {
-    string16 expected_title16(ASCIIToUTF16(expected_title));
+    base::string16 expected_title16(ASCIIToUTF16(expected_title));
     TitleWatcher title_watcher(shell()->web_contents(), expected_title16);
     NavigateToURL(shell(), url);
     EXPECT_EQ(expected_title16, title_watcher.WaitAndGetTitle());
   }
 
-  bool GetPopupTitle(const GURL& url, string16* title) {
+  bool GetPopupTitle(const GURL& url, base::string16* title) {
     NavigateToURL(shell(), url);
 
     ShellAddedObserver new_shell_observer;
@@ -96,7 +96,7 @@ IN_PROC_BROWSER_TEST_F(ResourceDispatcherHostBrowserTest, DynamicTitle1) {
   ASSERT_TRUE(embedded_test_server()->InitializeAndWaitUntilReady());
 
   GURL url(embedded_test_server()->GetURL("/dynamic1.html"));
-  string16 title;
+  base::string16 title;
   ASSERT_TRUE(GetPopupTitle(url, &title));
   EXPECT_TRUE(StartsWith(title, ASCIIToUTF16("My Popup Title"), true))
       << "Actual title: " << title;
@@ -108,7 +108,7 @@ IN_PROC_BROWSER_TEST_F(ResourceDispatcherHostBrowserTest, DynamicTitle2) {
   ASSERT_TRUE(embedded_test_server()->InitializeAndWaitUntilReady());
 
   GURL url(embedded_test_server()->GetURL("/dynamic2.html"));
-  string16 title;
+  base::string16 title;
   ASSERT_TRUE(GetPopupTitle(url, &title));
   EXPECT_TRUE(StartsWith(title, ASCIIToUTF16("My Dynamic Title"), true))
       << "Actual title: " << title;
@@ -364,7 +364,7 @@ IN_PROC_BROWSER_TEST_F(ResourceDispatcherHostBrowserTest,
   // URLs are prohibited by policy from interacting with sensitive chrome
   // pages of which the error page is one.  Instead, use automation to kick
   // off the navigation, and wait to see that the tab loads.
-  string16 expected_title16(ASCIIToUTF16("Title Of Awesomeness"));
+  base::string16 expected_title16(ASCIIToUTF16("Title Of Awesomeness"));
   TitleWatcher title_watcher(shell()->web_contents(), expected_title16);
 
   bool success;
diff --git a/content/browser/media/media_browsertest.cc b/content/browser/media/media_browsertest.cc
index 215b3e7..0655823 100644
--- a/content/browser/media/media_browsertest.cc
+++ b/content/browser/media/media_browsertest.cc
@@ -59,13 +59,13 @@ void MediaBrowserTest::RunMediaTestPage(
 }
 
 void MediaBrowserTest::RunTest(const GURL& gurl, const char* expected) {
-  const string16 expected_title = ASCIIToUTF16(expected);
+  const base::string16 expected_title = ASCIIToUTF16(expected);
   DVLOG(1) << "Running test URL: " << gurl;
   TitleWatcher title_watcher(shell()->web_contents(), expected_title);
   AddWaitForTitles(&title_watcher);
   NavigateToURL(shell(), gurl);
 
-  string16 final_title = title_watcher.WaitAndGetTitle();
+  base::string16 final_title = title_watcher.WaitAndGetTitle();
   EXPECT_EQ(expected_title, final_title);
 }
 
diff --git a/content/browser/media/media_internals.cc b/content/browser/media/media_internals.cc
index 1e0538e..1ee42d1 100644
--- a/content/browser/media/media_internals.cc
+++ b/content/browser/media/media_internals.cc
@@ -17,8 +17,8 @@ namespace {
 static base::LazyInstance<content::MediaInternals>::Leaky g_media_internals =
     LAZY_INSTANCE_INITIALIZER;
 
-string16 SerializeUpdate(const std::string& function,
-                         const base::Value* value) {
+base::string16 SerializeUpdate(const std::string& function,
+                               const base::Value* value) {
   return content::WebUI::GetJavascriptCall(
       function, std::vector<const base::Value*>(1, value));
 }
@@ -185,7 +185,7 @@ void MediaInternals::RemoveUpdateCallback(const UpdateCallback& callback) {
 }
 
 void MediaInternals::SendEverything() {
-  string16 everything_update;
+  base::string16 everything_update;
   {
     base::AutoLock auto_lock(lock_);
     everything_update = SerializeUpdate(
@@ -194,7 +194,7 @@ void MediaInternals::SendEverything() {
   SendUpdate(everything_update);
 }
 
-void MediaInternals::SendUpdate(const string16& update) {
+void MediaInternals::SendUpdate(const base::string16& update) {
   // SendUpdate() may be called from any thread, but must run on the IO thread.
   // TODO(dalecurtis): This is pretty silly since the update callbacks simply
   // forward the calls to the UI thread.  We should avoid the extra hop.
diff --git a/content/browser/media/media_internals.h b/content/browser/media/media_internals.h
index 8a179e0..c0f144a 100644
--- a/content/browser/media/media_internals.h
+++ b/content/browser/media/media_internals.h
@@ -37,7 +37,7 @@ class CONTENT_EXPORT MediaInternals
                      const std::vector<media::MediaLogEvent>& events);
 
   // Called with the update string.
-  typedef base::Callback<void(const string16&)> UpdateCallback;
+  typedef base::Callback<void(const base::string16&)> UpdateCallback;
 
   // Add/remove update callbacks (see above).  Must be called on the IO thread.
   void AddUpdateCallback(const UpdateCallback& callback);
@@ -59,7 +59,7 @@ class CONTENT_EXPORT MediaInternals
 
   // Sends |update| to each registered UpdateCallback.  Safe to call from any
   // thread, but will forward to the IO thread.
-  void SendUpdate(const string16& update);
+  void SendUpdate(const base::string16& update);
 
   // Caches |value| under |cache_key| so that future SendEverything() calls will
   // include the current data.  Calls JavaScript |function|(|value|) for each
diff --git a/content/browser/media/media_internals_handler.cc b/content/browser/media/media_internals_handler.cc
index a45dd4f..9a3e7be 100644
--- a/content/browser/media/media_internals_handler.cc
+++ b/content/browser/media/media_internals_handler.cc
@@ -38,12 +38,12 @@ void MediaInternalsMessageHandler::OnGetEverything(
   proxy_->GetEverything();
 }
 
-void MediaInternalsMessageHandler::OnUpdate(const string16& update) {
+void MediaInternalsMessageHandler::OnUpdate(const base::string16& update) {
   // Don't try to execute JavaScript in a RenderView that no longer exists nor
   // if the chrome://media-internals page hasn't finished loading.
   RenderViewHost* host = web_ui()->GetWebContents()->GetRenderViewHost();
   if (host && page_load_complete_)
-    host->ExecuteJavascriptInWebFrame(string16(), update);
+    host->ExecuteJavascriptInWebFrame(base::string16(), update);
 }
 
 }  // namespace content
diff --git a/content/browser/media/media_internals_handler.h b/content/browser/media/media_internals_handler.h
index 8ea6f88..265c122 100644
--- a/content/browser/media/media_internals_handler.h
+++ b/content/browser/media/media_internals_handler.h
@@ -30,7 +30,7 @@ class MediaInternalsMessageHandler : public WebUIMessageHandler {
   void OnGetEverything(const base::ListValue* list);
 
   // MediaInternals message handlers.
-  void OnUpdate(const string16& update);
+  void OnUpdate(const base::string16& update);
 
  private:
   scoped_refptr<MediaInternalsProxy> proxy_;
diff --git a/content/browser/media/media_internals_proxy.cc b/content/browser/media/media_internals_proxy.cc
index d0e0622..49456ab 100644
--- a/content/browser/media/media_internals_proxy.cc
+++ b/content/browser/media/media_internals_proxy.cc
@@ -69,7 +69,7 @@ void MediaInternalsProxy::GetEverything() {
   CallJavaScriptFunctionOnUIThread("media.onReceiveConstants", GetConstants());
 }
 
-void MediaInternalsProxy::OnUpdate(const string16& update) {
+void MediaInternalsProxy::OnUpdate(const base::string16& update) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
@@ -140,7 +140,7 @@ void MediaInternalsProxy::GetEverythingOnIOThread() {
   MediaInternals::GetInstance()->SendEverything();
 }
 
-void MediaInternalsProxy::UpdateUIOnUIThread(const string16& update) {
+void MediaInternalsProxy::UpdateUIOnUIThread(const base::string16& update) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // Don't forward updates to a destructed UI.
   if (handler_)
@@ -175,7 +175,7 @@ void MediaInternalsProxy::CallJavaScriptFunctionOnUIThread(
   scoped_ptr<base::Value> args_value(args);
   std::vector<const base::Value*> args_vector;
   args_vector.push_back(args_value.get());
-  string16 update = WebUI::GetJavascriptCall(function, args_vector);
+  base::string16 update = WebUI::GetJavascriptCall(function, args_vector);
   UpdateUIOnUIThread(update);
 }
 
diff --git a/content/browser/media/media_internals_proxy.h b/content/browser/media/media_internals_proxy.h
index 5d173b3..b737b85 100644
--- a/content/browser/media/media_internals_proxy.h
+++ b/content/browser/media/media_internals_proxy.h
@@ -49,7 +49,7 @@ class MediaInternalsProxy
   void GetEverything();
 
   // MediaInternals callback. Called on the IO thread.
-  void OnUpdate(const string16& update);
+  void OnUpdate(const base::string16& update);
 
   // net::NetLog::ThreadSafeObserver implementation. Callable from any thread:
   virtual void OnAddEntry(const net::NetLog::Entry& entry) OVERRIDE;
@@ -65,7 +65,7 @@ class MediaInternalsProxy
   void ObserveMediaInternalsOnIOThread();
   void StopObservingMediaInternalsOnIOThread();
   void GetEverythingOnIOThread();
-  void UpdateUIOnUIThread(const string16& update);
+  void UpdateUIOnUIThread(const base::string16& update);
 
   // Put |entry| on a list of events to be sent to the page.
   void AddNetEventOnUIThread(base::Value* entry);
diff --git a/content/browser/media/media_internals_unittest.cc b/content/browser/media/media_internals_unittest.cc
index e16124b..2947104 100644
--- a/content/browser/media/media_internals_unittest.cc
+++ b/content/browser/media/media_internals_unittest.cc
@@ -45,7 +45,7 @@ class MediaInternalsTest
 
  protected:
   // Extracts and deserializes the JSON update data; merges into |update_data_|.
-  void UpdateCallbackImpl(const string16& update) {
+  void UpdateCallbackImpl(const base::string16& update) {
     // Each update string looks like "<JavaScript Function Name>({<JSON>});", to
     // use the JSON reader we need to strip out the JavaScript code.
     std::string utf8_update = base::UTF16ToUTF8(update);
diff --git a/content/browser/media/webrtc_browsertest.cc b/content/browser/media/webrtc_browsertest.cc
index bfb96e1..e63207d 100644
--- a/content/browser/media/webrtc_browsertest.cc
+++ b/content/browser/media/webrtc_browsertest.cc
@@ -130,7 +130,7 @@ class WebrtcBrowserTest: public ContentBrowserTest {
   }
 
   void ExpectTitle(const std::string& expected_title) const {
-    string16 expected_title16(ASCIIToUTF16(expected_title));
+    base::string16 expected_title16(ASCIIToUTF16(expected_title));
     TitleWatcher title_watcher(shell()->web_contents(), expected_title16);
     EXPECT_EQ(expected_title16, title_watcher.WaitAndGetTitle());
   }
diff --git a/content/browser/media/webrtc_internals_browsertest.cc b/content/browser/media/webrtc_internals_browsertest.cc
index b458276..0d279b3 100644
--- a/content/browser/media/webrtc_internals_browsertest.cc
+++ b/content/browser/media/webrtc_internals_browsertest.cc
@@ -145,7 +145,7 @@ class MAYBE_WebRTCInternalsBrowserTest: public ContentBrowserTest {
   }
 
   void ExpectTitle(const std::string& expected_title) const {
-    string16 expected_title16(ASCIIToUTF16(expected_title));
+    base::string16 expected_title16(ASCIIToUTF16(expected_title));
     TitleWatcher title_watcher(shell()->web_contents(), expected_title16);
     EXPECT_EQ(expected_title16, title_watcher.WaitAndGetTitle());
   }
diff --git a/content/browser/media/webrtc_internals_message_handler.cc b/content/browser/media/webrtc_internals_message_handler.cc
index 2ba7522..8cf8579 100644
--- a/content/browser/media/webrtc_internals_message_handler.cc
+++ b/content/browser/media/webrtc_internals_message_handler.cc
@@ -68,11 +68,11 @@ void WebRTCInternalsMessageHandler::OnUpdate(const std::string& command,
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   std::vector<const base::Value*> args_vector;
   args_vector.push_back(args);
-  string16 update = WebUI::GetJavascriptCall(command, args_vector);
+  base::string16 update = WebUI::GetJavascriptCall(command, args_vector);
 
   RenderViewHost* host = web_ui()->GetWebContents()->GetRenderViewHost();
   if (host)
-    host->ExecuteJavascriptInWebFrame(string16(), update);
+    host->ExecuteJavascriptInWebFrame(base::string16(), update);
 }
 
 }  // namespace content
diff --git a/content/browser/message_port_service.cc b/content/browser/message_port_service.cc
index bc2a1ac..0d9f608 100644
--- a/content/browser/message_port_service.cc
+++ b/content/browser/message_port_service.cc
@@ -108,7 +108,7 @@ void MessagePortService::Entangle(int local_message_port_id,
 
 void MessagePortService::PostMessage(
     int sender_message_port_id,
-    const string16& message,
+    const base::string16& message,
     const std::vector<int>& sent_message_port_ids) {
   if (!message_ports_.count(sender_message_port_id)) {
     NOTREACHED();
@@ -130,7 +130,7 @@ void MessagePortService::PostMessage(
 
 void MessagePortService::PostMessageTo(
     int message_port_id,
-    const string16& message,
+    const base::string16& message,
     const std::vector<int>& sent_message_port_ids) {
   if (!message_ports_.count(message_port_id)) {
     NOTREACHED();
diff --git a/content/browser/message_port_service.h b/content/browser/message_port_service.h
index 55e536c..6689591 100644
--- a/content/browser/message_port_service.h
+++ b/content/browser/message_port_service.h
@@ -19,7 +19,8 @@ class MessagePortMessageFilter;
 
 class MessagePortService {
  public:
-  typedef std::vector<std::pair<string16, std::vector<int> > > QueuedMessages;
+  typedef std::vector<std::pair<base::string16, std::vector<int> > >
+      QueuedMessages;
 
   // Returns the MessagePortService singleton.
   static MessagePortService* GetInstance();
@@ -31,7 +32,7 @@ class MessagePortService {
   void Destroy(int message_port_id);
   void Entangle(int local_message_port_id, int remote_message_port_id);
   void PostMessage(int sender_message_port_id,
-                   const string16& message,
+                   const base::string16& message,
                    const std::vector<int>& sent_message_port_ids);
   void QueueMessages(int message_port_id);
   void SendQueuedMessages(int message_port_id,
@@ -56,7 +57,7 @@ class MessagePortService {
   ~MessagePortService();
 
   void PostMessageTo(int message_port_id,
-                     const string16& message,
+                     const base::string16& message,
                      const std::vector<int>& sent_message_port_ids);
 
   // Handles the details of removing a message port id. Before calling this,
diff --git a/content/browser/plugin_browsertest.cc b/content/browser/plugin_browsertest.cc
index 2a846f1..204a143 100644
--- a/content/browser/plugin_browsertest.cc
+++ b/content/browser/plugin_browsertest.cc
@@ -83,12 +83,12 @@ class PluginTest : public ContentBrowserTest {
   }
 
   static void LoadAndWaitInWindow(Shell* window, const GURL& url) {
-    string16 expected_title(ASCIIToUTF16("OK"));
+    base::string16 expected_title(ASCIIToUTF16("OK"));
     TitleWatcher title_watcher(window->web_contents(), expected_title);
     title_watcher.AlsoWaitForTitle(ASCIIToUTF16("FAIL"));
     title_watcher.AlsoWaitForTitle(ASCIIToUTF16("plugin_not_found"));
     NavigateToURL(window, url);
-    string16 title = title_watcher.WaitAndGetTitle();
+    base::string16 title = title_watcher.WaitAndGetTitle();
     if (title == ASCIIToUTF16("plugin_not_found")) {
       const testing::TestInfo* const test_info =
           testing::UnitTest::GetInstance()->current_test_info();
@@ -170,7 +170,7 @@ IN_PROC_BROWSER_TEST_F(PluginTest,
                        MAYBE(SelfDeletePluginInvokeInSynchronousMouseUp)) {
   NavigateToURL(shell(), GetURL("execute_script_delete_in_mouse_up.html"));
 
-  string16 expected_title(ASCIIToUTF16("OK"));
+  base::string16 expected_title(ASCIIToUTF16("OK"));
   TitleWatcher title_watcher(shell()->web_contents(), expected_title);
   title_watcher.AlsoWaitForTitle(ASCIIToUTF16("FAIL"));
   SimulateMouseClick(shell()->web_contents(), 0,
@@ -201,7 +201,7 @@ IN_PROC_BROWSER_TEST_F(PluginTest, MAYBE(SelfDeletePluginInvokeAlert)) {
   // race condition where the alert can come up before we start watching for it.
   shell()->LoadURL(GetURL("self_delete_plugin_invoke_alert.html"));
 
-  string16 expected_title(ASCIIToUTF16("OK"));
+  base::string16 expected_title(ASCIIToUTF16("OK"));
   TitleWatcher title_watcher(shell()->web_contents(), expected_title);
   title_watcher.AlsoWaitForTitle(ASCIIToUTF16("FAIL"));
 
@@ -408,7 +408,7 @@ IN_PROC_BROWSER_TEST_F(PluginTest, DISABLED_PluginConvertPointTest) {
 
   NavigateToURL(shell(), GetURL("convert_point.html"));
 
-  string16 expected_title(ASCIIToUTF16("OK"));
+  base::string16 expected_title(ASCIIToUTF16("OK"));
   TitleWatcher title_watcher(shell()->web_contents(), expected_title);
   title_watcher.AlsoWaitForTitle(ASCIIToUTF16("FAIL"));
   // TODO(stuartmorgan): When the automation system supports sending clicks,
diff --git a/content/browser/plugin_loader_posix_unittest.cc b/content/browser/plugin_loader_posix_unittest.cc
index 8f90723..13620f7 100644
--- a/content/browser/plugin_loader_posix_unittest.cc
+++ b/content/browser/plugin_loader_posix_unittest.cc
@@ -64,11 +64,11 @@ class PluginLoaderPosixTest : public testing::Test {
  public:
   PluginLoaderPosixTest()
       : plugin1_(ASCIIToUTF16("plugin1"), base::FilePath("/tmp/one.plugin"),
-                 ASCIIToUTF16("1.0"), string16()),
+                 ASCIIToUTF16("1.0"), base::string16()),
         plugin2_(ASCIIToUTF16("plugin2"), base::FilePath("/tmp/two.plugin"),
-                 ASCIIToUTF16("2.0"), string16()),
+                 ASCIIToUTF16("2.0"), base::string16()),
         plugin3_(ASCIIToUTF16("plugin3"), base::FilePath("/tmp/three.plugin"),
-                 ASCIIToUTF16("3.0"), string16()),
+                 ASCIIToUTF16("3.0"), base::string16()),
         file_thread_(BrowserThread::FILE, &message_loop_),
         io_thread_(BrowserThread::IO, &message_loop_),
         plugin_loader_(new MockPluginLoaderPosix) {
diff --git a/content/browser/plugin_service_impl.cc b/content/browser/plugin_service_impl.cc
index 1ddcf40..96216c1 100644
--- a/content/browser/plugin_service_impl.cc
+++ b/content/browser/plugin_service_impl.cc
@@ -547,9 +547,9 @@ bool PluginServiceImpl::GetPluginInfoByPath(const base::FilePath& plugin_path,
   return false;
 }
 
-string16 PluginServiceImpl::GetPluginDisplayNameByPath(
+base::string16 PluginServiceImpl::GetPluginDisplayNameByPath(
     const base::FilePath& path) {
-  string16 plugin_name = path.LossyDisplayName();
+  base::string16 plugin_name = path.LossyDisplayName();
   WebPluginInfo info;
   if (PluginService::GetInstance()->GetPluginInfoByPath(path, &info) &&
       !info.name.empty()) {
diff --git a/content/browser/plugin_service_impl.h b/content/browser/plugin_service_impl.h
index 11fb257..c7d95af 100644
--- a/content/browser/plugin_service_impl.h
+++ b/content/browser/plugin_service_impl.h
@@ -91,7 +91,7 @@ class CONTENT_EXPORT PluginServiceImpl
                              std::string* actual_mime_type) OVERRIDE;
   virtual bool GetPluginInfoByPath(const base::FilePath& plugin_path,
                                    WebPluginInfo* info) OVERRIDE;
-  virtual string16 GetPluginDisplayNameByPath(
+  virtual base::string16 GetPluginDisplayNameByPath(
       const base::FilePath& path) OVERRIDE;
   virtual void GetPlugins(const GetPluginsCallback& callback) OVERRIDE;
   virtual PepperPluginInfo* GetRegisteredPpapiPluginInfo(
diff --git a/content/browser/power_save_blocker_win.cc b/content/browser/power_save_blocker_win.cc
index fce72c6..cf9bb02 100644
--- a/content/browser/power_save_blocker_win.cc
+++ b/content/browser/power_save_blocker_win.cc
@@ -39,7 +39,7 @@ HANDLE CreatePowerRequest(POWER_REQUEST_TYPE type, const std::string& reason) {
     if (!PowerCreateRequestFn || !PowerSetRequestFn)
       return INVALID_HANDLE_VALUE;
   }
-  string16 wide_reason = ASCIIToUTF16(reason);
+  base::string16 wide_reason = ASCIIToUTF16(reason);
   REASON_CONTEXT context = {0};
   context.Version = POWER_REQUEST_CONTEXT_VERSION;
   context.Flags = POWER_REQUEST_CONTEXT_SIMPLE_STRING;
diff --git a/content/browser/ppapi_plugin_process_host.cc b/content/browser/ppapi_plugin_process_host.cc
index fbf512a..f6c9fd5 100644
--- a/content/browser/ppapi_plugin_process_host.cc
+++ b/content/browser/ppapi_plugin_process_host.cc
@@ -178,7 +178,7 @@ void PpapiPluginProcessHost::DidDeleteOutOfProcessInstance(
 
 // static
 void PpapiPluginProcessHost::FindByName(
-    const string16& name,
+    const base::string16& name,
     std::vector<PpapiPluginProcessHost*>* hosts) {
   for (PpapiPluginProcessHostIterator iter; !iter.Done(); ++iter) {
     if (iter->process_.get() && iter->process_->GetData().name == name)
diff --git a/content/browser/ppapi_plugin_process_host.h b/content/browser/ppapi_plugin_process_host.h
index 87c79c3..594c12f 100644
--- a/content/browser/ppapi_plugin_process_host.h
+++ b/content/browser/ppapi_plugin_process_host.h
@@ -92,7 +92,7 @@ class PpapiPluginProcessHost : public BrowserChildProcessHostDelegate,
 
   // Returns the instances that match the specified process name.
   // It can only be called on the IO thread.
-  static void FindByName(const string16& name,
+  static void FindByName(const base::string16& name,
                          std::vector<PpapiPluginProcessHost*>* hosts);
 
   // IPC::Sender implementation:
diff --git a/content/browser/renderer_host/clipboard_message_filter.cc b/content/browser/renderer_host/clipboard_message_filter.cc
index ae365d5..6ba95f8 100644
--- a/content/browser/renderer_host/clipboard_message_filter.cc
+++ b/content/browser/renderer_host/clipboard_message_filter.cc
@@ -145,9 +145,10 @@ void ClipboardMessageFilter::OnGetSequenceNumber(ui::ClipboardType type,
   *sequence_number = GetClipboard()->GetSequenceNumber(type);
 }
 
-void ClipboardMessageFilter::OnReadAvailableTypes(ui::ClipboardType type,
-                                                  std::vector<string16>* types,
-                                                  bool* contains_filenames) {
+void ClipboardMessageFilter::OnReadAvailableTypes(
+    ui::ClipboardType type,
+    std::vector<base::string16>* types,
+    bool* contains_filenames) {
   GetClipboard()->ReadAvailableTypes(type, types, contains_filenames);
 }
 
@@ -163,7 +164,7 @@ void ClipboardMessageFilter::OnClear(ui::ClipboardType type) {
 }
 
 void ClipboardMessageFilter::OnReadText(ui::ClipboardType type,
-                                        string16* result) {
+                                        base::string16* result) {
   GetClipboard()->ReadText(type, result);
 }
 
@@ -173,7 +174,7 @@ void ClipboardMessageFilter::OnReadAsciiText(ui::ClipboardType type,
 }
 
 void ClipboardMessageFilter::OnReadHTML(ui::ClipboardType type,
-                                        string16* markup,
+                                        base::string16* markup,
                                         GURL* url,
                                         uint32* fragment_start,
                                         uint32* fragment_end) {
@@ -224,8 +225,8 @@ void ClipboardMessageFilter::OnReadImageReply(
 }
 
 void ClipboardMessageFilter::OnReadCustomData(ui::ClipboardType clipboard_type,
-                                              const string16& type,
-                                              string16* result) {
+                                              const base::string16& type,
+                                              base::string16* result) {
   GetClipboard()->ReadCustomData(clipboard_type, type, result);
 }
 
diff --git a/content/browser/renderer_host/clipboard_message_filter.h b/content/browser/renderer_host/clipboard_message_filter.h
index 3ae7d1b..dd2784b 100644
--- a/content/browser/renderer_host/clipboard_message_filter.h
+++ b/content/browser/renderer_host/clipboard_message_filter.h
@@ -39,12 +39,12 @@ class ClipboardMessageFilter : public BrowserMessageFilter {
                            bool* result);
   void OnClear(ui::ClipboardType type);
   void OnReadAvailableTypes(ui::ClipboardType type,
-                            std::vector<string16>* types,
+                            std::vector<base::string16>* types,
                             bool* contains_filenames);
-  void OnReadText(ui::ClipboardType type, string16* result);
+  void OnReadText(ui::ClipboardType type, base::string16* result);
   void OnReadAsciiText(ui::ClipboardType type, std::string* result);
   void OnReadHTML(ui::ClipboardType type,
-                  string16* markup,
+                  base::string16* markup,
                   GURL* url,
                   uint32* fragment_start,
                   uint32* fragment_end);
@@ -52,13 +52,13 @@ class ClipboardMessageFilter : public BrowserMessageFilter {
   void OnReadImage(ui::ClipboardType type, IPC::Message* reply_msg);
   void OnReadImageReply(const SkBitmap& bitmap, IPC::Message* reply_msg);
   void OnReadCustomData(ui::ClipboardType clipboard_type,
-                        const string16& type,
-                        string16* result);
+                        const base::string16& type,
+                        base::string16* result);
   void OnReadData(const ui::Clipboard::FormatType& format,
                   std::string* data);
 
 #if defined(OS_MACOSX)
-  void OnFindPboardWriteString(const string16& text);
+  void OnFindPboardWriteString(const base::string16& text);
 #endif
 
   // We have our own clipboard because we want to access the clipboard on the
diff --git a/content/browser/renderer_host/clipboard_message_filter_mac.mm b/content/browser/renderer_host/clipboard_message_filter_mac.mm
index ee8f5a3..3c59d31 100644
--- a/content/browser/renderer_host/clipboard_message_filter_mac.mm
+++ b/content/browser/renderer_host/clipboard_message_filter_mac.mm
@@ -40,7 +40,8 @@ class WriteFindPboardWrapper {
 }  // namespace
 
 // Called on the IO thread.
-void ClipboardMessageFilter::OnFindPboardWriteString(const string16& text) {
+void ClipboardMessageFilter::OnFindPboardWriteString(
+    const base::string16& text) {
   if (text.length() <= kMaxFindPboardStringLength) {
     NSString* nsText = base::SysUTF16ToNSString(text);
     if (nsText) {
diff --git a/content/browser/renderer_host/database_message_filter.cc b/content/browser/renderer_host/database_message_filter.cc
index d41be65..55ea305 100644
--- a/content/browser/renderer_host/database_message_filter.cc
+++ b/content/browser/renderer_host/database_message_filter.cc
@@ -113,13 +113,14 @@ bool DatabaseMessageFilter::OnMessageReceived(
 DatabaseMessageFilter::~DatabaseMessageFilter() {
 }
 
-void DatabaseMessageFilter::OnDatabaseOpenFile(const string16& vfs_file_name,
-                                               int desired_flags,
-                                               IPC::Message* reply_msg) {
+void DatabaseMessageFilter::OnDatabaseOpenFile(
+    const base::string16& vfs_file_name,
+    int desired_flags,
+    IPC::Message* reply_msg) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   base::PlatformFile file_handle = base::kInvalidPlatformFileValue;
   std::string origin_identifier;
-  string16 database_name;
+  base::string16 database_name;
 
   // When in incognito mode, we want to make sure that all DB files are
   // removed when the incognito browser context goes away, so we add the
@@ -162,16 +163,18 @@ void DatabaseMessageFilter::OnDatabaseOpenFile(const string16& vfs_file_name,
   Send(reply_msg);
 }
 
-void DatabaseMessageFilter::OnDatabaseDeleteFile(const string16& vfs_file_name,
-                                                 const bool& sync_dir,
-                                                 IPC::Message* reply_msg) {
+void DatabaseMessageFilter::OnDatabaseDeleteFile(
+    const base::string16& vfs_file_name,
+    const bool& sync_dir,
+    IPC::Message* reply_msg) {
   DatabaseDeleteFile(vfs_file_name, sync_dir, reply_msg, kNumDeleteRetries);
 }
 
-void DatabaseMessageFilter::DatabaseDeleteFile(const string16& vfs_file_name,
-                                               bool sync_dir,
-                                               IPC::Message* reply_msg,
-                                               int reschedule_count) {
+void DatabaseMessageFilter::DatabaseDeleteFile(
+    const base::string16& vfs_file_name,
+    bool sync_dir,
+    IPC::Message* reply_msg,
+    int reschedule_count) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 
   // Return an error if the file name is invalid or if the file could not
@@ -183,8 +186,8 @@ void DatabaseMessageFilter::DatabaseDeleteFile(const string16& vfs_file_name,
     // In order to delete a journal file in incognito mode, we only need to
     // close the open handle to it that's stored in the database tracker.
     if (db_tracker_->IsIncognitoProfile()) {
-      const string16 wal_suffix(ASCIIToUTF16("-wal"));
-      string16 sqlite_suffix;
+      const base::string16 wal_suffix(ASCIIToUTF16("-wal"));
+      base::string16 sqlite_suffix;
 
       // WAL files can be deleted without having previously been opened.
       if (!db_tracker_->HasSavedIncognitoFileHandle(vfs_file_name) &&
@@ -215,7 +218,7 @@ void DatabaseMessageFilter::DatabaseDeleteFile(const string16& vfs_file_name,
 }
 
 void DatabaseMessageFilter::OnDatabaseGetFileAttributes(
-    const string16& vfs_file_name,
+    const base::string16& vfs_file_name,
     IPC::Message* reply_msg) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   int32 attributes = -1;
@@ -230,7 +233,7 @@ void DatabaseMessageFilter::OnDatabaseGetFileAttributes(
 }
 
 void DatabaseMessageFilter::OnDatabaseGetFileSize(
-    const string16& vfs_file_name, IPC::Message* reply_msg) {
+    const base::string16& vfs_file_name, IPC::Message* reply_msg) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   int64 size = 0;
   base::FilePath db_file =
@@ -278,8 +281,8 @@ void DatabaseMessageFilter::OnDatabaseGetUsageAndQuota(
 
 void DatabaseMessageFilter::OnDatabaseOpened(
     const std::string& origin_identifier,
-    const string16& database_name,
-    const string16& description,
+    const base::string16& database_name,
+    const base::string16& description,
     int64 estimated_size) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 
@@ -299,7 +302,7 @@ void DatabaseMessageFilter::OnDatabaseOpened(
 
 void DatabaseMessageFilter::OnDatabaseModified(
     const std::string& origin_identifier,
-    const string16& database_name) {
+    const base::string16& database_name) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   if (!database_connections_.IsDatabaseOpened(
           origin_identifier, database_name)) {
@@ -313,7 +316,7 @@ void DatabaseMessageFilter::OnDatabaseModified(
 
 void DatabaseMessageFilter::OnDatabaseClosed(
     const std::string& origin_identifier,
-    const string16& database_name) {
+    const base::string16& database_name) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   if (!database_connections_.IsDatabaseOpened(
           origin_identifier, database_name)) {
@@ -328,7 +331,7 @@ void DatabaseMessageFilter::OnDatabaseClosed(
 
 void DatabaseMessageFilter::OnHandleSqliteError(
     const std::string& origin_identifier,
-    const string16& database_name,
+    const base::string16& database_name,
     int error) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   if (!DatabaseUtil::IsValidOriginIdentifier(origin_identifier)) {
@@ -342,7 +345,7 @@ void DatabaseMessageFilter::OnHandleSqliteError(
 
 void DatabaseMessageFilter::OnDatabaseSizeChanged(
     const std::string& origin_identifier,
-    const string16& database_name,
+    const base::string16& database_name,
     int64 database_size) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   if (database_connections_.IsOriginUsed(origin_identifier)) {
@@ -353,7 +356,7 @@ void DatabaseMessageFilter::OnDatabaseSizeChanged(
 
 void DatabaseMessageFilter::OnDatabaseScheduledForDeletion(
     const std::string& origin_identifier,
-    const string16& database_name) {
+    const base::string16& database_name) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   Send(new DatabaseMsg_CloseImmediately(origin_identifier, database_name));
 }
diff --git a/content/browser/renderer_host/database_message_filter.h b/content/browser/renderer_host/database_message_filter.h
index 9e168c5..5024335 100644
--- a/content/browser/renderer_host/database_message_filter.h
+++ b/content/browser/renderer_host/database_message_filter.h
@@ -41,15 +41,15 @@ class DatabaseMessageFilter
   void RemoveObserver();
 
   // VFS message handlers (file thread)
-  void OnDatabaseOpenFile(const string16& vfs_file_name,
+  void OnDatabaseOpenFile(const base::string16& vfs_file_name,
                           int desired_flags,
                           IPC::Message* reply_msg);
-  void OnDatabaseDeleteFile(const string16& vfs_file_name,
+  void OnDatabaseDeleteFile(const base::string16& vfs_file_name,
                             const bool& sync_dir,
                             IPC::Message* reply_msg);
-  void OnDatabaseGetFileAttributes(const string16& vfs_file_name,
+  void OnDatabaseGetFileAttributes(const base::string16& vfs_file_name,
                                    IPC::Message* reply_msg);
-  void OnDatabaseGetFileSize(const string16& vfs_file_name,
+  void OnDatabaseGetFileSize(const base::string16& vfs_file_name,
                              IPC::Message* reply_msg);
 
   // Quota message handler (io thread)
@@ -62,26 +62,26 @@ class DatabaseMessageFilter
 
   // Database tracker message handlers (file thread)
   void OnDatabaseOpened(const std::string& origin_identifier,
-                        const string16& database_name,
-                        const string16& description,
+                        const base::string16& database_name,
+                        const base::string16& description,
                         int64 estimated_size);
   void OnDatabaseModified(const std::string& origin_identifier,
-                          const string16& database_name);
+                          const base::string16& database_name);
   void OnDatabaseClosed(const std::string& origin_identifier,
-                        const string16& database_name);
+                        const base::string16& database_name);
   void OnHandleSqliteError(const std::string& origin_identifier,
-                           const string16& database_name,
+                           const base::string16& database_name,
                            int error);
 
   // DatabaseTracker::Observer callbacks (file thread)
   virtual void OnDatabaseSizeChanged(const std::string& origin_identifier,
-                                     const string16& database_name,
+                                     const base::string16& database_name,
                                      int64 database_size) OVERRIDE;
   virtual void OnDatabaseScheduledForDeletion(
       const std::string& origin_identifier,
-      const string16& database_name) OVERRIDE;
+      const base::string16& database_name) OVERRIDE;
 
-  void DatabaseDeleteFile(const string16& vfs_file_name,
+  void DatabaseDeleteFile(const base::string16& vfs_file_name,
                           bool sync_dir,
                           IPC::Message* reply_msg,
                           int reschedule_count);
diff --git a/content/browser/renderer_host/gtk_im_context_wrapper.cc b/content/browser/renderer_host/gtk_im_context_wrapper.cc
index 7ce6558..d4b7789 100644
--- a/content/browser/renderer_host/gtk_im_context_wrapper.cc
+++ b/content/browser/renderer_host/gtk_im_context_wrapper.cc
@@ -477,7 +477,7 @@ void GtkIMContextWrapper::ConfirmComposition() {
     if (host_view_->GetRenderWidgetHost()) {
       RenderWidgetHostImpl::From(
           host_view_->GetRenderWidgetHost())->ImeConfirmComposition(
-              string16(), gfx::Range::InvalidRange(), false);
+              base::string16(), gfx::Range::InvalidRange(), false);
     }
 
     // Reset the input method.
@@ -485,7 +485,7 @@ void GtkIMContextWrapper::ConfirmComposition() {
   }
 }
 
-void GtkIMContextWrapper::HandleCommit(const string16& text) {
+void GtkIMContextWrapper::HandleCommit(const base::string16& text) {
   if (suppress_next_commit_)
     return;
 
diff --git a/content/browser/renderer_host/gtk_im_context_wrapper.h b/content/browser/renderer_host/gtk_im_context_wrapper.h
index 1647df1..8bd027f 100644
--- a/content/browser/renderer_host/gtk_im_context_wrapper.h
+++ b/content/browser/renderer_host/gtk_im_context_wrapper.h
@@ -75,7 +75,7 @@ class GtkIMContextWrapper {
   void ProcessInputMethodResult(const GdkEventKey* event, bool filtered);
 
   // Real code of "commit" signal handler.
-  void HandleCommit(const string16& text);
+  void HandleCommit(const base::string16& text);
 
   // Real code of "preedit-start" signal handler.
   void HandlePreeditStart();
@@ -180,7 +180,7 @@ class GtkIMContextWrapper {
 
   // Stores a copy of the most recent commit text received by commit signal
   // handler.
-  string16 commit_text_;
+  base::string16 commit_text_;
 
   // If it's true then the next "commit" signal will be suppressed.
   // It's only used to workaround http://crbug.com/50485.
diff --git a/content/browser/renderer_host/ime_adapter_android.cc b/content/browser/renderer_host/ime_adapter_android.cc
index 9e7fe47..92d972f 100644
--- a/content/browser/renderer_host/ime_adapter_android.cc
+++ b/content/browser/renderer_host/ime_adapter_android.cc
@@ -136,7 +136,7 @@ void ImeAdapterAndroid::SetComposingText(JNIEnv* env, jobject, jstring text,
   if (!rwhi)
     return;
 
-  string16 text16 = ConvertJavaStringToUTF16(env, text);
+  base::string16 text16 = ConvertJavaStringToUTF16(env, text);
   std::vector<blink::WebCompositionUnderline> underlines;
   underlines.push_back(
       blink::WebCompositionUnderline(0, text16.length(), SK_ColorBLACK,
@@ -155,7 +155,7 @@ void ImeAdapterAndroid::CommitText(JNIEnv* env, jobject, jstring text) {
   if (!rwhi)
     return;
 
-  string16 text16 = ConvertJavaStringToUTF16(env, text);
+  base::string16 text16 = ConvertJavaStringToUTF16(env, text);
   rwhi->ImeConfirmComposition(text16, gfx::Range::InvalidRange(), false);
 }
 
@@ -164,7 +164,8 @@ void ImeAdapterAndroid::FinishComposingText(JNIEnv* env, jobject) {
   if (!rwhi)
     return;
 
-  rwhi->ImeConfirmComposition(string16(), gfx::Range::InvalidRange(), true);
+  rwhi->ImeConfirmComposition(base::string16(), gfx::Range::InvalidRange(),
+                              true);
 }
 
 void ImeAdapterAndroid::AttachImeAdapter(JNIEnv* env, jobject java_object) {
diff --git a/content/browser/renderer_host/java/java_bridge_dispatcher_host.cc b/content/browser/renderer_host/java/java_bridge_dispatcher_host.cc
index 6d792e7..562517a 100644
--- a/content/browser/renderer_host/java/java_bridge_dispatcher_host.cc
+++ b/content/browser/renderer_host/java/java_bridge_dispatcher_host.cc
@@ -59,7 +59,7 @@ JavaBridgeDispatcherHost::~JavaBridgeDispatcherHost() {
       base::Bind(&CleanUpStubs, stubs_));
 }
 
-void JavaBridgeDispatcherHost::AddNamedObject(const string16& name,
+void JavaBridgeDispatcherHost::AddNamedObject(const base::string16& name,
                                               NPObject* object) {
   NPVariant_Param variant_param;
   CreateNPVariantParam(object, &variant_param);
@@ -68,7 +68,7 @@ void JavaBridgeDispatcherHost::AddNamedObject(const string16& name,
       render_view_host_->GetRoutingID(), name, variant_param));
 }
 
-void JavaBridgeDispatcherHost::RemoveNamedObject(const string16& name) {
+void JavaBridgeDispatcherHost::RemoveNamedObject(const base::string16& name) {
   // On receipt of this message, the JavaBridgeDispatcher will drop its
   // reference to the corresponding proxy object. When the last reference is
   // removed, the proxy object will delete its NPObjectProxy, which will cause
diff --git a/content/browser/renderer_host/java/java_bridge_dispatcher_host.h b/content/browser/renderer_host/java/java_bridge_dispatcher_host.h
index 94ee632..21e47c0 100644
--- a/content/browser/renderer_host/java/java_bridge_dispatcher_host.h
+++ b/content/browser/renderer_host/java/java_bridge_dispatcher_host.h
@@ -42,8 +42,8 @@ class JavaBridgeDispatcherHost
   // to |object|, which is manipulated on the background thread. This class
   // holds a reference to |object| for the time that the proxy object is bound
   // to the window object.
-  void AddNamedObject(const string16& name, NPObject* object);
-  void RemoveNamedObject(const string16& name);
+  void AddNamedObject(const base::string16& name, NPObject* object);
+  void RemoveNamedObject(const base::string16& name);
 
   // Since this object is ref-counted, it might outlive render_view_host_.
   void RenderViewDeleted();
diff --git a/content/browser/renderer_host/java/java_bridge_dispatcher_host_manager.cc b/content/browser/renderer_host/java/java_bridge_dispatcher_host_manager.cc
index f06d9fe..02cf4dc 100644
--- a/content/browser/renderer_host/java/java_bridge_dispatcher_host_manager.cc
+++ b/content/browser/renderer_host/java/java_bridge_dispatcher_host_manager.cc
@@ -31,7 +31,7 @@ JavaBridgeDispatcherHostManager::~JavaBridgeDispatcherHostManager() {
   DCHECK_EQ(0U, instances_.size());
 }
 
-void JavaBridgeDispatcherHostManager::AddNamedObject(const string16& name,
+void JavaBridgeDispatcherHostManager::AddNamedObject(const base::string16& name,
                                                      NPObject* object) {
   // Record this object in a map so that we can add it into RenderViewHosts
   // created later. The JavaBridgeDispatcherHost instances will take a
@@ -67,7 +67,8 @@ void JavaBridgeDispatcherHostManager::SetRetainedObjectSet(
   }
 }
 
-void JavaBridgeDispatcherHostManager::RemoveNamedObject(const string16& name) {
+void JavaBridgeDispatcherHostManager::RemoveNamedObject(
+    const base::string16& name) {
   ObjectMap::iterator iter = objects_.find(name);
   if (iter == objects_.end()) {
     return;
diff --git a/content/browser/renderer_host/java/java_bridge_dispatcher_host_manager.h b/content/browser/renderer_host/java/java_bridge_dispatcher_host_manager.h
index e3d629a..29523b5 100644
--- a/content/browser/renderer_host/java/java_bridge_dispatcher_host_manager.h
+++ b/content/browser/renderer_host/java/java_bridge_dispatcher_host_manager.h
@@ -34,8 +34,8 @@ class JavaBridgeDispatcherHostManager
   // These methods add or remove the object to each JavaBridgeDispatcherHost.
   // Each one holds a reference to the NPObject while the object is bound to
   // the corresponding RenderView. See JavaBridgeDispatcherHost for details.
-  void AddNamedObject(const string16& name, NPObject* object);
-  void RemoveNamedObject(const string16& name);
+  void AddNamedObject(const base::string16& name, NPObject* object);
+  void RemoveNamedObject(const base::string16& name);
 
   void OnGetChannelHandle(RenderViewHost* render_view_host,
                           IPC::Message* reply_msg);
@@ -60,7 +60,7 @@ class JavaBridgeDispatcherHostManager
   typedef std::map<RenderViewHost*, scoped_refptr<JavaBridgeDispatcherHost> >
       InstanceMap;
   InstanceMap instances_;
-  typedef std::map<string16, NPObject*> ObjectMap;
+  typedef std::map<base::string16, NPObject*> ObjectMap;
   ObjectMap objects_;
   JavaObjectWeakGlobalRef retained_object_set_;
 
diff --git a/content/browser/renderer_host/pepper/pepper_truetype_font_list_win.cc b/content/browser/renderer_host/pepper/pepper_truetype_font_list_win.cc
index e5cdcc6..3530e1e 100644
--- a/content/browser/renderer_host/pepper/pepper_truetype_font_list_win.cc
+++ b/content/browser/renderer_host/pepper/pepper_truetype_font_list_win.cc
@@ -73,7 +73,7 @@ void GetFontsInFamily_SlowBlocking(const std::string& family,
   LOGFONTW logfont;
   memset(&logfont, 0, sizeof(logfont));
   logfont.lfCharSet = DEFAULT_CHARSET;
-  string16 family16 = UTF8ToUTF16(family);
+  base::string16 family16 = UTF8ToUTF16(family);
   memcpy(&logfont.lfFaceName, &family16[0], sizeof(logfont.lfFaceName));
   base::win::ScopedCreateDC hdc(::CreateCompatibleDC(NULL));
   ::EnumFontFamiliesExW(hdc, &logfont, (FONTENUMPROCW)&EnumFontsInFamilyProc,
diff --git a/content/browser/renderer_host/render_message_filter.cc b/content/browser/renderer_host/render_message_filter.cc
index 3aca534..10a3901 100644
--- a/content/browser/renderer_host/render_message_filter.cc
+++ b/content/browser/renderer_host/render_message_filter.cc
@@ -843,7 +843,7 @@ void RenderMessageFilter::OnGetMonitorColorProfile(std::vector<char>* profile) {
 void RenderMessageFilter::OnDownloadUrl(const IPC::Message& message,
                                         const GURL& url,
                                         const Referrer& referrer,
-                                        const string16& suggested_name) {
+                                        const base::string16& suggested_name) {
   scoped_ptr<DownloadSaveInfo> save_info(new DownloadSaveInfo());
   save_info->suggested_name = suggested_name;
   scoped_ptr<net::URLRequest> request(
@@ -1112,7 +1112,7 @@ void RenderMessageFilter::OnDidLose3DContext(
 
 #if defined(OS_WIN)
 void RenderMessageFilter::OnPreCacheFontCharacters(const LOGFONT& font,
-                                                   const string16& str) {
+                                                   const base::string16& str) {
   // First, comments from FontCacheDispatcher::OnPreCacheFont do apply here too.
   // Except that for True Type fonts,
   // GetTextMetrics will not load the font in memory.
diff --git a/content/browser/renderer_host/render_message_filter.h b/content/browser/renderer_host/render_message_filter.h
index 526849e..23483a4 100644
--- a/content/browser/renderer_host/render_message_filter.h
+++ b/content/browser/renderer_host/render_message_filter.h
@@ -156,7 +156,7 @@ class RenderMessageFilter : public BrowserMessageFilter {
 
 #if defined(OS_WIN)
   void OnPreCacheFontCharacters(const LOGFONT& log_font,
-                                const string16& characters);
+                                const base::string16& characters);
 #endif
 
   void OnGetPlugins(bool refresh, IPC::Message* reply_msg);
@@ -190,7 +190,7 @@ class RenderMessageFilter : public BrowserMessageFilter {
   void OnDownloadUrl(const IPC::Message& message,
                      const GURL& url,
                      const Referrer& referrer,
-                     const string16& suggested_name);
+                     const base::string16& suggested_name);
   void OnCheckNotificationPermission(const GURL& source_origin,
                                      int* permission_level);
 
diff --git a/content/browser/renderer_host/render_view_host_delegate.cc b/content/browser/renderer_host/render_view_host_delegate.cc
index d7b8ba5..4786909 100644
--- a/content/browser/renderer_host/render_view_host_delegate.cc
+++ b/content/browser/renderer_host/render_view_host_delegate.cc
@@ -24,8 +24,8 @@ bool RenderViewHostDelegate::OnMessageReceived(RenderViewHost* render_view_host,
 }
 
 bool RenderViewHostDelegate::AddMessageToConsole(
-    int32 level, const string16& message, int32 line_no,
-    const string16& source_id) {
+    int32 level, const base::string16& message, int32 line_no,
+    const base::string16& source_id) {
   return false;
 }
 
diff --git a/content/browser/renderer_host/render_view_host_delegate.h b/content/browser/renderer_host/render_view_host_delegate.h
index f3bf8aa..e5fa672 100644
--- a/content/browser/renderer_host/render_view_host_delegate.h
+++ b/content/browser/renderer_host/render_view_host_delegate.h
@@ -195,7 +195,7 @@ class CONTENT_EXPORT RenderViewHostDelegate {
   // The page's title was changed and should be updated.
   virtual void UpdateTitle(RenderViewHost* render_view_host,
                            int32 page_id,
-                           const string16& title,
+                           const base::string16& title,
                            base::i18n::TextDirection title_direction) {}
 
   // The page's encoding was changed and should be updated.
@@ -281,23 +281,23 @@ class CONTENT_EXPORT RenderViewHostDelegate {
 
   // A javascript message, confirmation or prompt should be shown.
   virtual void RunJavaScriptMessage(RenderViewHost* rvh,
-                                    const string16& message,
-                                    const string16& default_prompt,
+                                    const base::string16& message,
+                                    const base::string16& default_prompt,
                                     const GURL& frame_url,
                                     JavaScriptMessageType type,
                                     IPC::Message* reply_msg,
                                     bool* did_suppress_message) {}
 
   virtual void RunBeforeUnloadConfirm(RenderViewHost* rvh,
-                                      const string16& message,
+                                      const base::string16& message,
                                       bool is_reload,
                                       IPC::Message* reply_msg) {}
 
   // A message was added to to the console.
   virtual bool AddMessageToConsole(int32 level,
-                                   const string16& message,
+                                   const base::string16& message,
                                    int32 line_no,
-                                   const string16& source_id);
+                                   const base::string16& source_id);
 
   // Return a dummy RendererPreferences object that will be used by the renderer
   // associated with the owning RenderViewHost.
diff --git a/content/browser/renderer_host/render_view_host_impl.cc b/content/browser/renderer_host/render_view_host_impl.cc
index 92d4fa5..6382706 100644
--- a/content/browser/renderer_host/render_view_host_impl.cc
+++ b/content/browser/renderer_host/render_view_host_impl.cc
@@ -243,7 +243,7 @@ SiteInstance* RenderViewHostImpl::GetSiteInstance() const {
 }
 
 bool RenderViewHostImpl::CreateRenderView(
-    const string16& frame_name,
+    const base::string16& frame_name,
     int opener_route_id,
     int32 max_page_id) {
   TRACE_EVENT0("renderer_host", "RenderViewHostImpl::CreateRenderView");
@@ -948,8 +948,9 @@ void RenderViewHostImpl::DesktopNotificationPostDisplay(int callback_context) {
                                               callback_context));
 }
 
-void RenderViewHostImpl::DesktopNotificationPostError(int notification_id,
-                                                      const string16& message) {
+void RenderViewHostImpl::DesktopNotificationPostError(
+    int notification_id,
+    const base::string16& message) {
   Send(new DesktopNotificationMsg_PostError(
       GetRoutingID(), notification_id, message));
 }
@@ -965,15 +966,15 @@ void RenderViewHostImpl::DesktopNotificationPostClick(int notification_id) {
 }
 
 void RenderViewHostImpl::ExecuteJavascriptInWebFrame(
-    const string16& frame_xpath,
-    const string16& jscript) {
+    const base::string16& frame_xpath,
+    const base::string16& jscript) {
   Send(new ViewMsg_ScriptEvalRequest(GetRoutingID(), frame_xpath, jscript,
                                      0, false));
 }
 
 void RenderViewHostImpl::ExecuteJavascriptInWebFrameCallbackResult(
-     const string16& frame_xpath,
-     const string16& jscript,
+     const base::string16& frame_xpath,
+     const base::string16& jscript,
      const JavascriptResultCallback& callback) {
   static int next_id = 1;
   int key = next_id++;
@@ -982,9 +983,10 @@ void RenderViewHostImpl::ExecuteJavascriptInWebFrameCallbackResult(
   javascript_callbacks_.insert(std::make_pair(key, callback));
 }
 
-void RenderViewHostImpl::JavaScriptDialogClosed(IPC::Message* reply_msg,
-                                                bool success,
-                                                const string16& user_input) {
+void RenderViewHostImpl::JavaScriptDialogClosed(
+    IPC::Message* reply_msg,
+    bool success,
+    const base::string16& user_input) {
   GetProcess()->SetIgnoreInputEvents(false);
   bool is_waiting =
       is_waiting_for_beforeunload_ack_ || is_waiting_for_unload_ack_;
@@ -1535,7 +1537,7 @@ void RenderViewHostImpl::OnUpdateState(int32 page_id, const PageState& state) {
 
 void RenderViewHostImpl::OnUpdateTitle(
     int32 page_id,
-    const string16& title,
+    const base::string16& title,
     blink::WebTextDirection title_direction) {
   if (title.length() > kMaxTitleChars) {
     NOTREACHED() << "Renderer sent too many characters in title.";
@@ -1669,7 +1671,7 @@ void RenderViewHostImpl::OnDidChangeScrollOffsetPinningForMainFrame(
 void RenderViewHostImpl::OnDidChangeNumWheelEvents(int count) {
 }
 
-void RenderViewHostImpl::OnSelectionChanged(const string16& text,
+void RenderViewHostImpl::OnSelectionChanged(const base::string16& text,
                                             size_t offset,
                                             const gfx::Range& range) {
   if (view_)
@@ -1695,8 +1697,8 @@ void RenderViewHostImpl::OnRouteMessageEvent(
 }
 
 void RenderViewHostImpl::OnRunJavaScriptMessage(
-    const string16& message,
-    const string16& default_prompt,
+    const base::string16& message,
+    const base::string16& default_prompt,
     const GURL& frame_url,
     JavaScriptMessageType type,
     IPC::Message* reply_msg) {
@@ -1710,7 +1712,7 @@ void RenderViewHostImpl::OnRunJavaScriptMessage(
 }
 
 void RenderViewHostImpl::OnRunBeforeUnloadConfirm(const GURL& frame_url,
-                                                  const string16& message,
+                                                  const base::string16& message,
                                                   bool is_reload,
                                                   IPC::Message* reply_msg) {
   // While a JS before unload dialog is showing, tabs in the same process
@@ -1789,9 +1791,9 @@ void RenderViewHostImpl::OnFocusedNodeChanged(bool is_editable_node) {
 
 void RenderViewHostImpl::OnAddMessageToConsole(
     int32 level,
-    const string16& message,
+    const base::string16& message,
     int32 line_no,
-    const string16& source_id) {
+    const base::string16& source_id) {
   if (delegate_->AddMessageToConsole(level, message, line_no, source_id))
     return;
 
@@ -2076,12 +2078,12 @@ void RenderViewHostImpl::ReloadFrame() {
 }
 
 void RenderViewHostImpl::Find(int request_id,
-                              const string16& search_text,
+                              const base::string16& search_text,
                               const blink::WebFindOptions& options) {
   Send(new ViewMsg_Find(GetRoutingID(), request_id, search_text, options));
 }
 
-void RenderViewHostImpl::InsertCSS(const string16& frame_xpath,
+void RenderViewHostImpl::InsertCSS(const base::string16& frame_xpath,
                                    const std::string& css) {
   Send(new ViewMsg_CSSInsertRequest(GetRoutingID(), frame_xpath, css));
 }
diff --git a/content/browser/renderer_host/render_view_host_impl.h b/content/browser/renderer_host/render_view_host_impl.h
index 424a787..6e02571 100644
--- a/content/browser/renderer_host/render_view_host_impl.h
+++ b/content/browser/renderer_host/render_view_host_impl.h
@@ -133,8 +133,9 @@ class CONTENT_EXPORT RenderViewHostImpl
   virtual void DesktopNotificationPermissionRequestDone(
       int callback_context) OVERRIDE;
   virtual void DesktopNotificationPostDisplay(int callback_context) OVERRIDE;
-  virtual void DesktopNotificationPostError(int notification_id,
-                                            const string16& message) OVERRIDE;
+  virtual void DesktopNotificationPostError(
+      int notification_id,
+      const base::string16& message) OVERRIDE;
   virtual void DesktopNotificationPostClose(int notification_id,
                                             bool by_user) OVERRIDE;
   virtual void DesktopNotificationPostClick(int notification_id) OVERRIDE;
@@ -172,17 +173,18 @@ class CONTENT_EXPORT RenderViewHostImpl
   virtual void ExecuteMediaPlayerActionAtLocation(
       const gfx::Point& location,
       const blink::WebMediaPlayerAction& action) OVERRIDE;
-  virtual void ExecuteJavascriptInWebFrame(const string16& frame_xpath,
-                                           const string16& jscript) OVERRIDE;
+  virtual void ExecuteJavascriptInWebFrame(
+      const base::string16& frame_xpath,
+      const base::string16& jscript) OVERRIDE;
   virtual void ExecuteJavascriptInWebFrameCallbackResult(
-      const string16& frame_xpath,
-      const string16& jscript,
+      const base::string16& frame_xpath,
+      const base::string16& jscript,
       const JavascriptResultCallback& callback) OVERRIDE;
   virtual void ExecutePluginActionAtLocation(
       const gfx::Point& location,
       const blink::WebPluginAction& action) OVERRIDE;
   virtual void ExitFullscreen() OVERRIDE;
-  virtual void Find(int request_id, const string16& search_text,
+  virtual void Find(int request_id, const base::string16& search_text,
                     const blink::WebFindOptions& options) OVERRIDE;
   virtual void StopFinding(StopFindAction action) OVERRIDE;
   virtual void FirePageBeforeUnload(bool for_cross_site_transition) OVERRIDE;
@@ -192,7 +194,7 @@ class CONTENT_EXPORT RenderViewHostImpl
   virtual RenderViewHostDelegate* GetDelegate() const OVERRIDE;
   virtual int GetEnabledBindings() const OVERRIDE;
   virtual SiteInstance* GetSiteInstance() const OVERRIDE;
-  virtual void InsertCSS(const string16& frame_xpath,
+  virtual void InsertCSS(const base::string16& frame_xpath,
                          const std::string& css) OVERRIDE;
   virtual bool IsRenderViewLive() const OVERRIDE;
   virtual bool IsSubframe() const OVERRIDE;
@@ -233,7 +235,7 @@ class CONTENT_EXPORT RenderViewHostImpl
   // The |opener_route_id| parameter indicates which RenderView created this
   // (MSG_ROUTING_NONE if none). If |max_page_id| is larger than -1, the
   // RenderView is told to start issuing page IDs at |max_page_id| + 1.
-  virtual bool CreateRenderView(const string16& frame_name,
+  virtual bool CreateRenderView(const base::string16& frame_name,
                                 int opener_route_id,
                                 int32 max_page_id);
 
@@ -348,7 +350,7 @@ class CONTENT_EXPORT RenderViewHostImpl
   // closed by the user.
   void JavaScriptDialogClosed(IPC::Message* reply_msg,
                               bool success,
-                              const string16& user_input);
+                              const base::string16& user_input);
 
   // Tells the renderer view to focus the first (last if reverse is true) node.
   void SetInitialFocus(bool reverse);
@@ -534,7 +536,7 @@ class CONTENT_EXPORT RenderViewHostImpl
   void OnNavigate(const IPC::Message& msg);
   void OnUpdateState(int32 page_id, const PageState& state);
   void OnUpdateTitle(int32 page_id,
-                     const string16& title,
+                     const base::string16& title,
                      blink::WebTextDirection title_direction);
   void OnUpdateEncoding(const std::string& encoding);
   void OnUpdateTargetURL(int32 page_id, const GURL& url);
@@ -556,7 +558,7 @@ class CONTENT_EXPORT RenderViewHostImpl
   void OnDidChangeScrollOffsetPinningForMainFrame(bool is_pinned_to_left,
                                                   bool is_pinned_to_right);
   void OnDidChangeNumWheelEvents(int count);
-  void OnSelectionChanged(const string16& text,
+  void OnSelectionChanged(const base::string16& text,
                           size_t offset,
                           const gfx::Range& range);
   void OnSelectionBoundsChanged(
@@ -564,13 +566,13 @@ class CONTENT_EXPORT RenderViewHostImpl
   void OnPasteFromSelectionClipboard();
   void OnRouteCloseEvent();
   void OnRouteMessageEvent(const ViewMsg_PostMessage_Params& params);
-  void OnRunJavaScriptMessage(const string16& message,
-                              const string16& default_prompt,
+  void OnRunJavaScriptMessage(const base::string16& message,
+                              const base::string16& default_prompt,
                               const GURL& frame_url,
                               JavaScriptMessageType type,
                               IPC::Message* reply_msg);
   void OnRunBeforeUnloadConfirm(const GURL& frame_url,
-                                const string16& message,
+                                const base::string16& message,
                                 bool is_reload,
                                 IPC::Message* reply_msg);
   void OnStartDragging(const DropData& drop_data,
@@ -583,9 +585,9 @@ class CONTENT_EXPORT RenderViewHostImpl
   void OnTakeFocus(bool reverse);
   void OnFocusedNodeChanged(bool is_editable_node);
   void OnAddMessageToConsole(int32 level,
-                             const string16& message,
+                             const base::string16& message,
                              int32 line_no,
-                             const string16& source_id);
+                             const base::string16& source_id);
   void OnUpdateInspectorSetting(const std::string& key,
                                 const std::string& value);
   void OnShouldCloseACK(
diff --git a/content/browser/renderer_host/render_view_host_unittest.cc b/content/browser/renderer_host/render_view_host_unittest.cc
index 67e08d2..3196097 100644
--- a/content/browser/renderer_host/render_view_host_unittest.cc
+++ b/content/browser/renderer_host/render_view_host_unittest.cc
@@ -199,7 +199,7 @@ TEST_F(RenderViewHostTest, DragEnteredFileURLsStillBlocked) {
   GURL sensitive_file_url = net::FilePathToFileURL(sensitive_file_path);
   dropped_data.url = highlighted_file_url;
   dropped_data.filenames.push_back(DropData::FileInfo(
-      UTF8ToUTF16(dragged_file_path.AsUTF8Unsafe()), string16()));
+      UTF8ToUTF16(dragged_file_path.AsUTF8Unsafe()), base::string16()));
 
   rvh()->DragTargetDragEnter(dropped_data, client_point, screen_point,
                               blink::WebDragOperationNone, 0);
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index 9cb8922..c792a6d 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -1321,7 +1321,7 @@ void RenderWidgetHostImpl::CandidateWindowHidden() {
 }
 
 void RenderWidgetHostImpl::ImeSetComposition(
-    const string16& text,
+    const base::string16& text,
     const std::vector<blink::WebCompositionUnderline>& underlines,
     int selection_start,
     int selection_end) {
@@ -1330,7 +1330,7 @@ void RenderWidgetHostImpl::ImeSetComposition(
 }
 
 void RenderWidgetHostImpl::ImeConfirmComposition(
-    const string16& text,
+    const base::string16& text,
     const gfx::Range& replacement_range,
     bool keep_selection) {
   Send(new ViewMsg_ImeConfirmComposition(
@@ -1338,7 +1338,7 @@ void RenderWidgetHostImpl::ImeConfirmComposition(
 }
 
 void RenderWidgetHostImpl::ImeCancelComposition() {
-  Send(new ViewMsg_ImeSetComposition(GetRoutingID(), string16(),
+  Send(new ViewMsg_ImeSetComposition(GetRoutingID(), base::string16(),
             std::vector<blink::WebCompositionUnderline>(), 0, 0));
 }
 
@@ -1442,7 +1442,7 @@ void RenderWidgetHostImpl::OnClose() {
 }
 
 void RenderWidgetHostImpl::OnSetTooltipText(
-    const string16& tooltip_text,
+    const base::string16& tooltip_text,
     WebTextDirection text_direction_hint) {
   // First, add directionality marks around tooltip text if necessary.
   // A naive solution would be to simply always wrap the text. However, on
@@ -1457,7 +1457,7 @@ void RenderWidgetHostImpl::OnSetTooltipText(
   // trying to detect the directionality from the tooltip text rather than the
   // element direction.  One could argue that would be a preferable solution
   // but we use the current approach to match Fx & IE's behavior.
-  string16 wrapped_tooltip_text = tooltip_text;
+  base::string16 wrapped_tooltip_text = tooltip_text;
   if (!tooltip_text.empty()) {
     if (text_direction_hint == blink::WebTextDirectionLeftToRight) {
       // Force the tooltip to have LTR directionality.
@@ -1935,11 +1935,11 @@ void RenderWidgetHostImpl::ScrollBackingStoreRect(const gfx::Vector2d& delta,
   backing_store->ScrollBackingStore(delta, clip_rect, view_size);
 }
 
-void RenderWidgetHostImpl::Replace(const string16& word) {
+void RenderWidgetHostImpl::Replace(const base::string16& word) {
   Send(new InputMsg_Replace(routing_id_, word));
 }
 
-void RenderWidgetHostImpl::ReplaceMisspelling(const string16& word) {
+void RenderWidgetHostImpl::ReplaceMisspelling(const base::string16& word) {
   Send(new InputMsg_ReplaceMisspelling(routing_id_, word));
 }
 
diff --git a/content/browser/renderer_host/render_widget_host_impl.h b/content/browser/renderer_host/render_widget_host_impl.h
index 66e2e9a..9b94a44 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -164,8 +164,8 @@ class CONTENT_EXPORT RenderWidgetHostImpl : virtual public RenderWidgetHost,
                            int tag,
                            const gfx::Size& page_size,
                            const gfx::Size& desired_size) OVERRIDE;
-  virtual void Replace(const string16& word) OVERRIDE;
-  virtual void ReplaceMisspelling(const string16& word) OVERRIDE;
+  virtual void Replace(const base::string16& word) OVERRIDE;
+  virtual void ReplaceMisspelling(const base::string16& word) OVERRIDE;
   virtual void ResizeRectChanged(const gfx::Rect& new_rect) OVERRIDE;
   virtual void RestartHangMonitorTimeout() OVERRIDE;
   virtual void SetIgnoreInputEvents(bool ignore_input_events) OVERRIDE;
@@ -333,7 +333,7 @@ class CONTENT_EXPORT RenderWidgetHostImpl : virtual public RenderWidgetHost,
   // * when it receives a "preedit_changed" signal of GtkIMContext (on Linux);
   // * when markedText of NSTextInput is called (on Mac).
   void ImeSetComposition(
-      const string16& text,
+      const base::string16& text,
       const std::vector<blink::WebCompositionUnderline>& underlines,
       int selection_start,
       int selection_end);
@@ -344,7 +344,7 @@ class CONTENT_EXPORT RenderWidgetHostImpl : virtual public RenderWidgetHost,
   //   (on Windows);
   // * when it receives a "commit" signal of GtkIMContext (on Linux);
   // * when insertText of NSTextInput is called (on Mac).
-  void ImeConfirmComposition(const string16& text,
+  void ImeConfirmComposition(const base::string16& text,
                              const gfx::Range& replacement_range,
                              bool keep_selection);
 
@@ -651,7 +651,7 @@ class CONTENT_EXPORT RenderWidgetHostImpl : virtual public RenderWidgetHost,
   void OnClose();
   void OnUpdateScreenRectsAck();
   void OnRequestMove(const gfx::Rect& pos);
-  void OnSetTooltipText(const string16& tooltip_text,
+  void OnSetTooltipText(const base::string16& tooltip_text,
                         blink::WebTextDirection text_direction_hint);
   void OnPaintAtSizeAck(int tag, const gfx::Size& size);
 #if defined(OS_MACOSX)
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index c8c559b..0c79dbd 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -524,11 +524,11 @@ void RenderWidgetHostViewAndroid::Destroy() {
 }
 
 void RenderWidgetHostViewAndroid::SetTooltipText(
-    const string16& tooltip_text) {
+    const base::string16& tooltip_text) {
   // Tooltips don't makes sense on Android.
 }
 
-void RenderWidgetHostViewAndroid::SelectionChanged(const string16& text,
+void RenderWidgetHostViewAndroid::SelectionChanged(const base::string16& text,
                                                    size_t offset,
                                                    const gfx::Range& range) {
   RenderWidgetHostViewBase::SelectionChanged(text, offset, range);
diff --git a/content/browser/renderer_host/render_widget_host_view_android.h b/content/browser/renderer_host/render_widget_host_view_android.h
index c01120f..537b87b 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.h
+++ b/content/browser/renderer_host/render_widget_host_view_android.h
@@ -112,8 +112,8 @@ class RenderWidgetHostViewAndroid
   virtual void RenderProcessGone(base::TerminationStatus status,
                                  int error_code) OVERRIDE;
   virtual void Destroy() OVERRIDE;
-  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE;
-  virtual void SelectionChanged(const string16& text,
+  virtual void SetTooltipText(const base::string16& tooltip_text) OVERRIDE;
+  virtual void SelectionChanged(const base::string16& text,
                                 size_t offset,
                                 const gfx::Range& range) OVERRIDE;
   virtual void SelectionBoundsChanged(
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index de6c1ed..27db1a4 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -990,7 +990,8 @@ void RenderWidgetHostViewAura::Destroy() {
   delete window_;
 }
 
-void RenderWidgetHostViewAura::SetTooltipText(const string16& tooltip_text) {
+void RenderWidgetHostViewAura::SetTooltipText(
+    const base::string16& tooltip_text) {
   tooltip_ = tooltip_text;
   aura::Window* root_window = window_->GetRootWindow();
   aura::client::TooltipClient* tooltip_client =
@@ -1002,7 +1003,7 @@ void RenderWidgetHostViewAura::SetTooltipText(const string16& tooltip_text) {
   }
 }
 
-void RenderWidgetHostViewAura::SelectionChanged(const string16& text,
+void RenderWidgetHostViewAura::SelectionChanged(const base::string16& text,
                                                 size_t offset,
                                                 const gfx::Range& range) {
   RenderWidgetHostViewBase::SelectionChanged(text, offset, range);
@@ -2180,8 +2181,10 @@ void RenderWidgetHostViewAura::SetCompositionText(
 }
 
 void RenderWidgetHostViewAura::ConfirmCompositionText() {
-  if (host_ && has_composition_text_)
-    host_->ImeConfirmComposition(string16(), gfx::Range::InvalidRange(), false);
+  if (host_ && has_composition_text_) {
+    host_->ImeConfirmComposition(base::string16(), gfx::Range::InvalidRange(),
+                                 false);
+  }
   has_composition_text_ = false;
 }
 
@@ -2191,7 +2194,7 @@ void RenderWidgetHostViewAura::ClearCompositionText() {
   has_composition_text_ = false;
 }
 
-void RenderWidgetHostViewAura::InsertText(const string16& text) {
+void RenderWidgetHostViewAura::InsertText(const base::string16& text) {
   DCHECK(text_input_type_ != ui::TEXT_INPUT_TYPE_NONE);
   if (host_)
     host_->ImeConfirmComposition(text, gfx::Range::InvalidRange(), false);
@@ -2326,7 +2329,7 @@ bool RenderWidgetHostViewAura::DeleteRange(const gfx::Range& range) {
 
 bool RenderWidgetHostViewAura::GetTextFromRange(
     const gfx::Range& range,
-    string16* text) const {
+    base::string16* text) const {
   gfx::Range selection_text_range(selection_text_offset_,
       selection_text_offset_ + selection_text_.length());
 
@@ -3252,8 +3255,10 @@ bool RenderWidgetHostViewAura::NeedsInputGrab() {
 void RenderWidgetHostViewAura::FinishImeCompositionSession() {
   if (!has_composition_text_)
     return;
-  if (host_)
-    host_->ImeConfirmComposition(string16(), gfx::Range::InvalidRange(), false);
+  if (host_) {
+    host_->ImeConfirmComposition(base::string16(), gfx::Range::InvalidRange(),
+                                 false);
+  }
   ImeCancelComposition();
 }
 
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.h b/content/browser/renderer_host/render_widget_host_view_aura.h
index 385495a..569209b 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.h
+++ b/content/browser/renderer_host/render_widget_host_view_aura.h
@@ -192,8 +192,8 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
   virtual void RenderProcessGone(base::TerminationStatus status,
                                  int error_code) OVERRIDE;
   virtual void Destroy() OVERRIDE;
-  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE;
-  virtual void SelectionChanged(const string16& text,
+  virtual void SetTooltipText(const base::string16& tooltip_text) OVERRIDE;
+  virtual void SelectionChanged(const base::string16& text,
                                 size_t offset,
                                 const gfx::Range& range) OVERRIDE;
   virtual void SelectionBoundsChanged(
@@ -258,7 +258,7 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
       const ui::CompositionText& composition) OVERRIDE;
   virtual void ConfirmCompositionText() OVERRIDE;
   virtual void ClearCompositionText() OVERRIDE;
-  virtual void InsertText(const string16& text) OVERRIDE;
+  virtual void InsertText(const base::string16& text) OVERRIDE;
   virtual void InsertChar(char16 ch, int flags) OVERRIDE;
   virtual gfx::NativeWindow GetAttachedWindow() const OVERRIDE;
   virtual ui::TextInputType GetTextInputType() const OVERRIDE;
@@ -274,7 +274,7 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
   virtual bool SetSelectionRange(const gfx::Range& range) OVERRIDE;
   virtual bool DeleteRange(const gfx::Range& range) OVERRIDE;
   virtual bool GetTextFromRange(const gfx::Range& range,
-                                string16* text) const OVERRIDE;
+                                base::string16* text) const OVERRIDE;
   virtual void OnInputMethodChanged() OVERRIDE;
   virtual bool ChangeTextDirectionAndLayoutAlignment(
       base::i18n::TextDirection direction) OVERRIDE;
@@ -619,7 +619,7 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
   bool accept_return_character_;
 
   // Current tooltip text.
-  string16 tooltip_;
+  base::string16 tooltip_;
 
   std::vector<base::Closure> on_compositing_did_commit_callbacks_;
 
diff --git a/content/browser/renderer_host/render_widget_host_view_base.cc b/content/browser/renderer_host/render_widget_host_view_base.cc
index b96182c..8347b6d 100644
--- a/content/browser/renderer_host/render_widget_host_view_base.cc
+++ b/content/browser/renderer_host/render_widget_host_view_base.cc
@@ -118,7 +118,7 @@ LRESULT CALLBACK PluginWrapperWindowProc(HWND window, unsigned int message,
 
 bool IsPluginWrapperWindow(HWND window) {
   return gfx::GetClassNameW(window) ==
-      string16(kWrapperNativeWindowClassName);
+      base::string16(kWrapperNativeWindowClassName);
 }
 
 // Create an intermediate window between the given HWND and its parent.
@@ -421,7 +421,7 @@ float RenderWidgetHostViewBase::GetOverdrawBottomHeight() const {
   return 0.f;
 }
 
-void RenderWidgetHostViewBase::SelectionChanged(const string16& text,
+void RenderWidgetHostViewBase::SelectionChanged(const base::string16& text,
                                                 size_t offset,
                                                 const gfx::Range& range) {
   selection_text_ = text;
@@ -439,9 +439,9 @@ void RenderWidgetHostViewBase::SetShowingContextMenu(bool showing) {
   showing_context_menu_ = showing;
 }
 
-string16 RenderWidgetHostViewBase::GetSelectedText() const {
+base::string16 RenderWidgetHostViewBase::GetSelectedText() const {
   if (!selection_range_.IsValid())
-    return string16();
+    return base::string16();
   return selection_text_.substr(
       selection_range_.GetMin() - selection_text_offset_,
       selection_range_.length());
diff --git a/content/browser/renderer_host/render_widget_host_view_base.h b/content/browser/renderer_host/render_widget_host_view_base.h
index 0a6fd1a..eadf92b 100644
--- a/content/browser/renderer_host/render_widget_host_view_base.h
+++ b/content/browser/renderer_host/render_widget_host_view_base.h
@@ -47,7 +47,7 @@ class CONTENT_EXPORT RenderWidgetHostViewBase
 
   // RenderWidgetHostViewPort implementation.
   virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
-  virtual void SelectionChanged(const string16& text,
+  virtual void SelectionChanged(const base::string16& text,
                                 size_t offset,
                                 const gfx::Range& range) OVERRIDE;
   virtual void SetBackground(const SkBitmap& background) OVERRIDE;
@@ -56,7 +56,7 @@ class CONTENT_EXPORT RenderWidgetHostViewBase
   virtual float GetOverdrawBottomHeight() const OVERRIDE;
   virtual bool IsShowingContextMenu() const OVERRIDE;
   virtual void SetShowingContextMenu(bool showing_menu) OVERRIDE;
-  virtual string16 GetSelectedText() const OVERRIDE;
+  virtual base::string16 GetSelectedText() const OVERRIDE;
   virtual bool IsMouseLocked() OVERRIDE;
   virtual void UnhandledWheelEvent(
       const blink::WebMouseWheelEvent& event) OVERRIDE;
@@ -140,7 +140,7 @@ class CONTENT_EXPORT RenderWidgetHostViewBase
   bool showing_context_menu_;
 
   // A buffer containing the text inside and around the current selection range.
-  string16 selection_text_;
+  base::string16 selection_text_;
 
   // The offset of the text stored in |selection_text_| relative to the start of
   // the web page.
diff --git a/content/browser/renderer_host/render_widget_host_view_gtk.cc b/content/browser/renderer_host/render_widget_host_view_gtk.cc
index 494ba38..18d3180 100644
--- a/content/browser/renderer_host/render_widget_host_view_gtk.cc
+++ b/content/browser/renderer_host/render_widget_host_view_gtk.cc
@@ -929,14 +929,15 @@ void RenderWidgetHostViewGtk::Destroy() {
   base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
 }
 
-void RenderWidgetHostViewGtk::SetTooltipText(const string16& tooltip_text) {
+void RenderWidgetHostViewGtk::SetTooltipText(
+    const base::string16& tooltip_text) {
   // Maximum number of characters we allow in a tooltip.
   const int kMaxTooltipLength = 8 << 10;
   // Clamp the tooltip length to kMaxTooltipLength so that we don't
   // accidentally DOS the user with a mega tooltip (since GTK doesn't do
   // this itself).
   // I filed https://bugzilla.gnome.org/show_bug.cgi?id=604641 upstream.
-  const string16 clamped_tooltip =
+  const base::string16 clamped_tooltip =
       gfx::TruncateString(tooltip_text, kMaxTooltipLength);
 
   if (clamped_tooltip.empty()) {
@@ -947,7 +948,7 @@ void RenderWidgetHostViewGtk::SetTooltipText(const string16& tooltip_text) {
   }
 }
 
-void RenderWidgetHostViewGtk::SelectionChanged(const string16& text,
+void RenderWidgetHostViewGtk::SelectionChanged(const base::string16& text,
                                                size_t offset,
                                                const gfx::Range& range) {
   RenderWidgetHostViewBase::SelectionChanged(text, offset, range);
@@ -1347,7 +1348,7 @@ bool RenderWidgetHostViewGtk::LockMouse() {
   }
 
   // Clear the tooltip window.
-  SetTooltipText(string16());
+  SetTooltipText(base::string16());
 
   // Ensure that the widget center location will be relevant for this mouse
   // lock session. It is updated whenever the window geometry moves
@@ -1411,7 +1412,7 @@ bool RenderWidgetHostViewGtk::RetrieveSurrounding(std::string* text,
 
   *text = base::UTF16ToUTF8AndAdjustOffset(
       base::StringPiece16(selection_text_), &offset);
-  if (offset == string16::npos) {
+  if (offset == base::string16::npos) {
     NOTREACHED() << "Invalid offset in UTF16 string.";
     return false;
   }
diff --git a/content/browser/renderer_host/render_widget_host_view_gtk.h b/content/browser/renderer_host/render_widget_host_view_gtk.h
index 9bb2755..e01181a 100644
--- a/content/browser/renderer_host/render_widget_host_view_gtk.h
+++ b/content/browser/renderer_host/render_widget_host_view_gtk.h
@@ -93,8 +93,8 @@ class CONTENT_EXPORT RenderWidgetHostViewGtk
                                  int error_code) OVERRIDE;
   virtual void Destroy() OVERRIDE;
   virtual void WillDestroyRenderWidget(RenderWidgetHost* rwh) {}
-  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE;
-  virtual void SelectionChanged(const string16& text,
+  virtual void SetTooltipText(const base::string16& tooltip_text) OVERRIDE;
+  virtual void SelectionChanged(const base::string16& text,
                                 size_t offset,
                                 const gfx::Range& range) OVERRIDE;
   virtual void SelectionBoundsChanged(
diff --git a/content/browser/renderer_host/render_widget_host_view_guest.cc b/content/browser/renderer_host/render_widget_host_view_guest.cc
index 6299384..49562c8 100644
--- a/content/browser/renderer_host/render_widget_host_view_guest.cc
+++ b/content/browser/renderer_host/render_widget_host_view_guest.cc
@@ -169,7 +169,8 @@ void RenderWidgetHostViewGuest::Destroy() {
   platform_view_->Destroy();
 }
 
-void RenderWidgetHostViewGuest::SetTooltipText(const string16& tooltip_text) {
+void RenderWidgetHostViewGuest::SetTooltipText(
+    const base::string16& tooltip_text) {
   platform_view_->SetTooltipText(tooltip_text);
 }
 
@@ -324,7 +325,7 @@ void RenderWidgetHostViewGuest::DidUpdateBackingStore(
   NOTREACHED();
 }
 
-void RenderWidgetHostViewGuest::SelectionChanged(const string16& text,
+void RenderWidgetHostViewGuest::SelectionChanged(const base::string16& text,
                                                  size_t offset,
                                                  const gfx::Range& range) {
   platform_view_->SelectionChanged(text, offset, range);
diff --git a/content/browser/renderer_host/render_widget_host_view_guest.h b/content/browser/renderer_host/render_widget_host_view_guest.h
index e406b50..ac9fa0e 100644
--- a/content/browser/renderer_host/render_widget_host_view_guest.h
+++ b/content/browser/renderer_host/render_widget_host_view_guest.h
@@ -98,8 +98,8 @@ class CONTENT_EXPORT RenderWidgetHostViewGuest
                                  int error_code) OVERRIDE;
   virtual void Destroy() OVERRIDE;
   virtual void WillDestroyRenderWidget(RenderWidgetHost* rwh) {}
-  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE;
-  virtual void SelectionChanged(const string16& text,
+  virtual void SetTooltipText(const base::string16& tooltip_text) OVERRIDE;
+  virtual void SelectionChanged(const base::string16& text,
                                 size_t offset,
                                 const gfx::Range& range) OVERRIDE;
   virtual void SelectionBoundsChanged(
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.h b/content/browser/renderer_host/render_widget_host_view_mac.h
index 4a667b0..ffacd53 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.h
+++ b/content/browser/renderer_host/render_widget_host_view_mac.h
@@ -108,10 +108,10 @@ class RenderWidgetHostViewMacEditCommandHelper;
   NSRange selectedRange_;
 
   // Text to be inserted which was generated by handling a key down event.
-  string16 textToBeInserted_;
+  base::string16 textToBeInserted_;
 
   // Marked text which was generated by handling a key down event.
-  string16 markedText_;
+  base::string16 markedText_;
 
   // Underline information of the |markedText_|.
   std::vector<blink::WebCompositionUnderline> underlines_;
@@ -264,8 +264,8 @@ class RenderWidgetHostViewMac : public RenderWidgetHostViewBase,
   virtual void RenderProcessGone(base::TerminationStatus status,
                                  int error_code) OVERRIDE;
   virtual void Destroy() OVERRIDE;
-  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE;
-  virtual void SelectionChanged(const string16& text,
+  virtual void SetTooltipText(const base::string16& tooltip_text) OVERRIDE;
+  virtual void SelectionChanged(const base::string16& text,
                                 size_t offset,
                                 const gfx::Range& range) OVERRIDE;
   virtual void SelectionBoundsChanged(
@@ -338,7 +338,7 @@ class RenderWidgetHostViewMac : public RenderWidgetHostViewBase,
   void EnableCoreAnimation();
 
   // Sends completed plugin IME notification and text back to the renderer.
-  void PluginImeCompositionCompleted(const string16& text, int plugin_id);
+  void PluginImeCompositionCompleted(const base::string16& text, int plugin_id);
 
   const std::string& selected_text() const { return selected_text_; }
 
@@ -526,7 +526,7 @@ class RenderWidgetHostViewMac : public RenderWidgetHostViewBase,
   bool is_loading_;
 
   // The text to be shown in the tooltip, supplied by the renderer.
-  string16 tooltip_text_;
+  base::string16 tooltip_text_;
 
   // Factory used to safely scope delayed calls to ShutdownHost().
   base::WeakPtrFactory<RenderWidgetHostViewMac> weak_factory_;
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.mm b/content/browser/renderer_host/render_widget_host_view_mac.mm
index b23b5d0..0069e73 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac.mm
@@ -1019,7 +1019,8 @@ void RenderWidgetHostViewMac::Destroy() {
 // Called from the renderer to tell us what the tooltip text should be. It
 // calls us frequently so we need to cache the value to prevent doing a lot
 // of repeat work.
-void RenderWidgetHostViewMac::SetTooltipText(const string16& tooltip_text) {
+void RenderWidgetHostViewMac::SetTooltipText(
+    const base::string16& tooltip_text) {
   if (tooltip_text != tooltip_text_ && [[cocoa_view_ window] isKeyWindow]) {
     tooltip_text_ = tooltip_text;
 
@@ -1027,7 +1028,7 @@ void RenderWidgetHostViewMac::SetTooltipText(const string16& tooltip_text) {
     // Windows; we're just trying to be polite. Don't persist the trimmed
     // string, as then the comparison above will always fail and we'll try to
     // set it again every single time the mouse moves.
-    string16 display_text = tooltip_text_;
+    base::string16 display_text = tooltip_text_;
     if (tooltip_text_.length() > kMaxTooltipLength)
       display_text = tooltip_text_.substr(0, kMaxTooltipLength);
 
@@ -1060,7 +1061,7 @@ void RenderWidgetHostViewMac::StopSpeaking() {
 // RenderWidgetHostViewCocoa uses the stored selection text,
 // which implements NSServicesRequests protocol.
 //
-void RenderWidgetHostViewMac::SelectionChanged(const string16& text,
+void RenderWidgetHostViewMac::SelectionChanged(const base::string16& text,
                                                size_t offset,
                                                const gfx::Range& range) {
   if (range.is_empty() || text.empty()) {
@@ -1245,7 +1246,7 @@ bool RenderWidgetHostViewMac::PostProcessEventForPluginIme(
 }
 
 void RenderWidgetHostViewMac::PluginImeCompositionCompleted(
-    const string16& text, int plugin_id) {
+    const base::string16& text, int plugin_id) {
   if (render_widget_host_) {
     render_widget_host_->Send(new ViewMsg_PluginImeCompositionCompleted(
         render_widget_host_->GetRoutingID(), text, plugin_id));
@@ -1745,7 +1746,7 @@ bool RenderWidgetHostViewMac::LockMouse() {
   [NSCursor hide];
 
   // Clear the tooltip window.
-  SetTooltipText(string16());
+  SetTooltipText(base::string16());
 
   return true;
 }
@@ -2399,7 +2400,7 @@ void RenderWidgetHostViewMac::FrameSwapped() {
   } else if (oldHasMarkedText && !hasMarkedText_ && !textInserted) {
     if (unmarkTextCalled_) {
       widgetHost->ImeConfirmComposition(
-          string16(), gfx::Range::InvalidRange(), false);
+          base::string16(), gfx::Range::InvalidRange(), false);
     } else {
       widgetHost->ImeCancelComposition();
     }
@@ -3512,7 +3513,7 @@ extern NSString *NSTextInputReplacementRangeAttributeName;
   // called in keyEvent: method.
   if (!handlingKeyDown_) {
     renderWidgetHostView_->render_widget_host_->ImeConfirmComposition(
-        string16(), gfx::Range::InvalidRange(), false);
+        base::string16(), gfx::Range::InvalidRange(), false);
   } else {
     unmarkTextCalled_ = YES;
   }
@@ -3750,7 +3751,7 @@ extern NSString *NSTextInputReplacementRangeAttributeName;
 
   if (renderWidgetHostView_->render_widget_host_)
     renderWidgetHostView_->render_widget_host_->ImeConfirmComposition(
-        string16(), gfx::Range::InvalidRange(), false);
+        base::string16(), gfx::Range::InvalidRange(), false);
 
   [self cancelComposition];
 }
@@ -3763,7 +3764,7 @@ extern NSString *NSTextInputReplacementRangeAttributeName;
   if (!active) {
     [[ComplexTextInputPanel sharedComplexTextInputPanel] cancelComposition];
     renderWidgetHostView_->PluginImeCompositionCompleted(
-        string16(), focusedPluginIdentifier_);
+        base::string16(), focusedPluginIdentifier_);
   }
 }
 
@@ -3798,7 +3799,7 @@ extern NSString *NSTextInputReplacementRangeAttributeName;
   if (pluginImeActive_ &&
       ![[ComplexTextInputPanel sharedComplexTextInputPanel] inComposition]) {
     renderWidgetHostView_->PluginImeCompositionCompleted(
-        string16(), focusedPluginIdentifier_);
+        base::string16(), focusedPluginIdentifier_);
     pluginImeActive_ = NO;
   }
 }
diff --git a/content/browser/renderer_host/render_widget_host_view_mac_unittest.mm b/content/browser/renderer_host/render_widget_host_view_mac_unittest.mm
index ad37bfd..0a4b795 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac_unittest.mm
+++ b/content/browser/renderer_host/render_widget_host_view_mac_unittest.mm
@@ -318,7 +318,7 @@ TEST_F(RenderWidgetHostViewMacTest, AcceleratorDestroy) {
 }
 
 TEST_F(RenderWidgetHostViewMacTest, GetFirstRectForCharacterRangeCaretCase) {
-  const string16 kDummyString = UTF8ToUTF16("hogehoge");
+  const base::string16 kDummyString = UTF8ToUTF16("hogehoge");
   const size_t kDummyOffset = 0;
 
   gfx::Rect caret_rect(10, 11, 0, 10);
diff --git a/content/browser/renderer_host/render_widget_host_view_win.cc b/content/browser/renderer_host/render_widget_host_view_win.cc
index c07a989..8238a82 100644
--- a/content/browser/renderer_host/render_widget_host_view_win.cc
+++ b/content/browser/renderer_host/render_widget_host_view_win.cc
@@ -836,14 +836,15 @@ void RenderWidgetHostViewWin::Destroy() {
   DestroyWindow();
 }
 
-void RenderWidgetHostViewWin::SetTooltipText(const string16& tooltip_text) {
+void RenderWidgetHostViewWin::SetTooltipText(
+    const base::string16& tooltip_text) {
   if (!render_widget_host_->is_hidden())
     EnsureTooltip();
 
   // Clamp the tooltip length to kMaxTooltipLength so that we don't
   // accidentally DOS the user with a mega tooltip (since Windows doesn't seem
   // to do this itself).
-  const string16 new_tooltip_text =
+  const base::string16 new_tooltip_text =
       gfx::TruncateString(tooltip_text, kMaxTooltipLength);
 
   if (new_tooltip_text != tooltip_text_) {
@@ -1017,7 +1018,7 @@ void RenderWidgetHostViewWin::ClearCompositionText() {
   NOTIMPLEMENTED();
 }
 
-void RenderWidgetHostViewWin::InsertText(const string16& text) {
+void RenderWidgetHostViewWin::InsertText(const base::string16& text) {
   if (!base::win::IsTSFAwareRequired()) {
     NOTREACHED();
     return;
@@ -1153,7 +1154,7 @@ bool RenderWidgetHostViewWin::DeleteRange(const gfx::Range& range) {
 }
 
 bool RenderWidgetHostViewWin::GetTextFromRange(const gfx::Range& range,
-                                               string16* text) const {
+                                               base::string16* text) const {
   if (!base::win::IsTSFAwareRequired()) {
     NOTREACHED();
     return false;
diff --git a/content/browser/renderer_host/render_widget_host_view_win.h b/content/browser/renderer_host/render_widget_host_view_win.h
index 72b22aa..b9a87bf 100644
--- a/content/browser/renderer_host/render_widget_host_view_win.h
+++ b/content/browser/renderer_host/render_widget_host_view_win.h
@@ -202,7 +202,7 @@ class RenderWidgetHostViewWin
   // called by WebContentsImpl before DestroyWindow
   virtual void WillWmDestroy() OVERRIDE;
   virtual void Destroy() OVERRIDE;
-  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE;
+  virtual void SetTooltipText(const base::string16& tooltip_text) OVERRIDE;
   virtual BackingStore* AllocBackingStore(const gfx::Size& size) OVERRIDE;
   virtual void CopyFromCompositingSurface(
       const gfx::Rect& src_subrect,
@@ -270,7 +270,7 @@ class RenderWidgetHostViewWin
       const ui::CompositionText& composition) OVERRIDE;
   virtual void ConfirmCompositionText() OVERRIDE;
   virtual void ClearCompositionText() OVERRIDE;
-  virtual void InsertText(const string16& text) OVERRIDE;
+  virtual void InsertText(const base::string16& text) OVERRIDE;
   virtual void InsertChar(char16 ch, int flags) OVERRIDE;
   virtual gfx::NativeWindow GetAttachedWindow() const OVERRIDE;
   virtual ui::TextInputType GetTextInputType() const OVERRIDE;
@@ -286,7 +286,7 @@ class RenderWidgetHostViewWin
   virtual bool SetSelectionRange(const gfx::Range& range) OVERRIDE;
   virtual bool DeleteRange(const gfx::Range& range) OVERRIDE;
   virtual bool GetTextFromRange(const gfx::Range& range,
-                                string16* text) const OVERRIDE;
+                                base::string16* text) const OVERRIDE;
   virtual void OnInputMethodChanged() OVERRIDE;
   virtual bool ChangeTextDirectionAndLayoutAlignment(
       base::i18n::TextDirection direction) OVERRIDE;
@@ -516,7 +516,7 @@ class RenderWidgetHostViewWin
 
   // Tooltips
   // The text to be shown in the tooltip, supplied by the renderer.
-  string16 tooltip_text_;
+  base::string16 tooltip_text_;
   // The tooltip control hwnd
   HWND tooltip_hwnd_;
   // Whether or not a tooltip is currently visible. We use this to track
diff --git a/content/browser/renderer_host/test_render_view_host.cc b/content/browser/renderer_host/test_render_view_host.cc
index 19d5958..4dfcf70 100644
--- a/content/browser/renderer_host/test_render_view_host.cc
+++ b/content/browser/renderer_host/test_render_view_host.cc
@@ -269,7 +269,7 @@ TestRenderViewHost::~TestRenderViewHost() {
 }
 
 bool TestRenderViewHost::CreateRenderView(
-    const string16& frame_name,
+    const base::string16& frame_name,
     int opener_route_id,
     int32 max_page_id) {
   DCHECK(!render_view_created_);
diff --git a/content/browser/renderer_host/test_render_view_host.h b/content/browser/renderer_host/test_render_view_host.h
index 97bcd6e..680f937 100644
--- a/content/browser/renderer_host/test_render_view_host.h
+++ b/content/browser/renderer_host/test_render_view_host.h
@@ -117,7 +117,7 @@ class TestRenderWidgetHostView : public RenderWidgetHostViewBase {
                                  int error_code) OVERRIDE;
   virtual void WillDestroyRenderWidget(RenderWidgetHost* rwh) { }
   virtual void Destroy() OVERRIDE;
-  virtual void SetTooltipText(const string16& tooltip_text) OVERRIDE {}
+  virtual void SetTooltipText(const base::string16& tooltip_text) OVERRIDE {}
   virtual void SelectionBoundsChanged(
       const ViewHostMsg_SelectionBounds_Params& params) OVERRIDE {}
   virtual void ScrollOffsetChanged() OVERRIDE {}
@@ -312,7 +312,7 @@ class TestRenderViewHost
 
   // RenderViewHost overrides --------------------------------------------------
 
-  virtual bool CreateRenderView(const string16& frame_name,
+  virtual bool CreateRenderView(const base::string16& frame_name,
                                 int opener_route_id,
                                 int32 max_page_id) OVERRIDE;
   virtual bool IsRenderViewLive() const OVERRIDE;
diff --git a/content/browser/session_history_browsertest.cc b/content/browser/session_history_browsertest.cc
index 7d006b6..bec8293 100644
--- a/content/browser/session_history_browsertest.cc
+++ b/content/browser/session_history_browsertest.cc
@@ -99,7 +99,7 @@ class SessionHistoryTest : public ContentBrowserTest {
 
   void NavigateAndCheckTitle(const char* filename,
                              const std::string& expected_title) {
-    string16 expected_title16(ASCIIToUTF16(expected_title));
+    base::string16 expected_title16(ASCIIToUTF16(expected_title));
     TitleWatcher title_watcher(shell()->web_contents(), expected_title16);
     NavigateToURL(shell(), GetURL(filename));
     ASSERT_EQ(expected_title16, title_watcher.WaitAndGetTitle());
diff --git a/content/browser/site_instance_impl_unittest.cc b/content/browser/site_instance_impl_unittest.cc
index 5524091..05b3ae7 100644
--- a/content/browser/site_instance_impl_unittest.cc
+++ b/content/browser/site_instance_impl_unittest.cc
@@ -204,7 +204,8 @@ TEST_F(SiteInstanceTest, SiteInstanceDestructor) {
   EXPECT_EQ(0, site_delete_counter);
 
   NavigationEntryImpl* e1 = new NavigationEntryImpl(
-      instance, 0, url, Referrer(), string16(), PAGE_TRANSITION_LINK, false);
+      instance, 0, url, Referrer(), base::string16(), PAGE_TRANSITION_LINK,
+      false);
 
   // Redundantly setting e1's SiteInstance shouldn't affect the ref count.
   e1->set_site_instance(instance);
@@ -212,7 +213,8 @@ TEST_F(SiteInstanceTest, SiteInstanceDestructor) {
 
   // Add a second reference
   NavigationEntryImpl* e2 = new NavigationEntryImpl(
-      instance, 0, url, Referrer(), string16(), PAGE_TRANSITION_LINK, false);
+      instance, 0, url, Referrer(), base::string16(), PAGE_TRANSITION_LINK,
+      false);
 
   // Now delete both entries and be sure the SiteInstance goes away.
   delete e1;
@@ -264,7 +266,8 @@ TEST_F(SiteInstanceTest, CloneNavigationEntry) {
                                                &browsing_delete_counter);
 
   NavigationEntryImpl* e1 = new NavigationEntryImpl(
-      instance1, 0, url, Referrer(), string16(), PAGE_TRANSITION_LINK, false);
+      instance1, 0, url, Referrer(), base::string16(), PAGE_TRANSITION_LINK,
+      false);
   // Clone the entry
   NavigationEntryImpl* e2 = new NavigationEntryImpl(*e1);
 
diff --git a/content/browser/site_per_process_browsertest.cc b/content/browser/site_per_process_browsertest.cc
index f32e1e9..cca1df0 100644
--- a/content/browser/site_per_process_browsertest.cc
+++ b/content/browser/site_per_process_browsertest.cc
@@ -36,11 +36,11 @@ class SitePerProcessWebContentsObserver: public WebContentsObserver {
 
   virtual void DidFailProvisionalLoad(
       int64 frame_id,
-      const string16& frame_unique_name,
+      const base::string16& frame_unique_name,
       bool is_main_frame,
       const GURL& validated_url,
       int error_code,
-      const string16& error_description,
+      const base::string16& error_description,
       RenderViewHost* render_view_host) OVERRIDE {
     navigation_url_ = validated_url;
     navigation_succeeded_ = false;
@@ -48,7 +48,7 @@ class SitePerProcessWebContentsObserver: public WebContentsObserver {
 
   virtual void DidCommitProvisionalLoadForFrame(
       int64 frame_id,
-      const string16& frame_unique_name,
+      const base::string16& frame_unique_name,
       bool is_main_frame,
       const GURL& url,
       PageTransition transition_type,
diff --git a/content/browser/speech/google_one_shot_remote_engine.cc b/content/browser/speech/google_one_shot_remote_engine.cc
index a421e79..575dd5f 100644
--- a/content/browser/speech/google_one_shot_remote_engine.cc
+++ b/content/browser/speech/google_one_shot_remote_engine.cc
@@ -121,7 +121,7 @@ bool ParseServerResponse(const std::string& response_body,
 
     const base::DictionaryValue* hypothesis_value =
         static_cast<const base::DictionaryValue*>(hypothesis);
-    string16 utterance;
+    base::string16 utterance;
 
     if (!hypothesis_value->GetString(kUtteranceString, &utterance)) {
       LOG(WARNING) << "ParseServerResponse: Missing utterance value.";
diff --git a/content/browser/speech/speech_recognition_manager_impl.cc b/content/browser/speech/speech_recognition_manager_impl.cc
index bdc9d1c..6ecfa70 100644
--- a/content/browser/speech/speech_recognition_manager_impl.cc
+++ b/content/browser/speech/speech_recognition_manager_impl.cc
@@ -672,7 +672,7 @@ bool SpeechRecognitionManagerImpl::HasAudioInputDevices() {
   return audio_manager_->HasAudioInputDevices();
 }
 
-string16 SpeechRecognitionManagerImpl::GetAudioInputDeviceModel() {
+base::string16 SpeechRecognitionManagerImpl::GetAudioInputDeviceModel() {
   return audio_manager_->GetAudioInputDeviceModel();
 }
 
diff --git a/content/browser/speech/speech_recognition_manager_impl.h b/content/browser/speech/speech_recognition_manager_impl.h
index 7db7d24..d471cf3 100644
--- a/content/browser/speech/speech_recognition_manager_impl.h
+++ b/content/browser/speech/speech_recognition_manager_impl.h
@@ -75,7 +75,7 @@ class CONTENT_EXPORT SpeechRecognitionManagerImpl :
                          int render_view_id,
                          int request_id) const OVERRIDE;
   virtual bool HasAudioInputDevices() OVERRIDE;
-  virtual string16 GetAudioInputDeviceModel() OVERRIDE;
+  virtual base::string16 GetAudioInputDeviceModel() OVERRIDE;
   virtual void ShowAudioInputSettings() OVERRIDE;
 
   // SpeechRecognitionEventListener methods.
diff --git a/content/browser/speech/speech_recognizer_impl_android.cc b/content/browser/speech/speech_recognizer_impl_android.cc
index c771cef..2e8c57e 100644
--- a/content/browser/speech/speech_recognizer_impl_android.cc
+++ b/content/browser/speech/speech_recognizer_impl_android.cc
@@ -146,7 +146,7 @@ void SpeechRecognizerImplAndroid::OnAudioEnd(JNIEnv* env, jobject obj) {
 void SpeechRecognizerImplAndroid::OnRecognitionResults(JNIEnv* env, jobject obj,
     jobjectArray strings, jfloatArray floats, jboolean provisional) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  std::vector<string16> options;
+  std::vector<base::string16> options;
   AppendJavaStringArrayToStringVector(env, strings, &options);
   std::vector<float> scores(options.size(), 0.0);
   if (floats != NULL)
diff --git a/content/browser/web_contents/touch_editable_impl_aura.cc b/content/browser/web_contents/touch_editable_impl_aura.cc
index 6f85625..ed002c7 100644
--- a/content/browser/web_contents/touch_editable_impl_aura.cc
+++ b/content/browser/web_contents/touch_editable_impl_aura.cc
@@ -307,7 +307,7 @@ bool TouchEditableImplAura::IsCommandIdEnabled(int command_id) const {
     case IDS_APP_COPY:
       return has_selection;
     case IDS_APP_PASTE: {
-      string16 result;
+      base::string16 result;
       ui::Clipboard::GetForCurrentThread()->ReadText(
           ui::CLIPBOARD_TYPE_COPY_PASTE, &result);
       return editable && !result.empty();
diff --git a/content/browser/web_contents/web_contents_drag_win.cc b/content/browser/web_contents/web_contents_drag_win.cc
index 3a59057..ffc8713 100644
--- a/content/browser/web_contents/web_contents_drag_win.cc
+++ b/content/browser/web_contents/web_contents_drag_win.cc
@@ -227,7 +227,7 @@ void WebContentsDragWin::PrepareDragForDownload(
     const GURL& page_url,
     const std::string& page_encoding) {
   // Parse the download metadata.
-  string16 mime_type;
+  base::string16 mime_type;
   base::FilePath file_name;
   GURL download_url;
   if (!ParseDownloadMetadata(drop_data.download_metadata,
@@ -284,7 +284,7 @@ void WebContentsDragWin::PrepareDragForFileContents(
   // Images without ALT text will only have a file extension so we need to
   // synthesize one from the provided extension and URL.
   if (file_name.BaseName().RemoveExtension().empty()) {
-    const string16 extension = file_name.Extension();
+    const base::string16 extension = file_name.Extension();
     // Retrieve the name from the URL.
     file_name = base::FilePath(
         net::GetSuggestedFilename(drop_data.url, "", "", "", "", ""));
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index e05cab0..7d04a60 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -348,7 +348,7 @@ WebContentsImpl::WebContentsImpl(
       crashed_status_(base::TERMINATION_STATUS_STILL_RUNNING),
       crashed_error_code_(0),
       waiting_for_response_(false),
-      load_state_(net::LOAD_STATE_IDLE, string16()),
+      load_state_(net::LOAD_STATE_IDLE, base::string16()),
       upload_size_(0),
       upload_position_(0),
       displayed_insecure_content_(false),
@@ -727,7 +727,7 @@ gfx::NativeViewAccessible accessible_parent) {
 }
 #endif
 
-const string16& WebContentsImpl::GetTitle() const {
+const base::string16& WebContentsImpl::GetTitle() const {
   // Transient entries take precedence. They are used for interstitial pages
   // that are shown on top of existing pages.
   NavigationEntry* entry = controller_.GetTransientEntry();
@@ -744,7 +744,7 @@ const string16& WebContentsImpl::GetTitle() const {
     entry = controller_.GetVisibleEntry();
     if (!(entry && entry->IsViewSourceMode())) {
       // Give the Web UI the chance to override our title.
-      const string16& title = our_web_ui->GetOverriddenTitle();
+      const base::string16& title = our_web_ui->GetOverriddenTitle();
       if (!title.empty())
         return title;
     }
@@ -832,7 +832,7 @@ const net::LoadStateWithParam& WebContentsImpl::GetLoadState() const {
   return load_state_;
 }
 
-const string16& WebContentsImpl::GetLoadStateHost() const {
+const base::string16& WebContentsImpl::GetLoadStateHost() const {
   return load_state_host_;
 }
 
@@ -2219,7 +2219,7 @@ void WebContentsImpl::OnDidFailLoadWithError(
     const GURL& url,
     bool is_main_frame,
     int error_code,
-    const string16& error_description) {
+    const base::string16& error_description) {
   GURL validated_url(url);
   RenderProcessHost* render_process_host = message_source_->GetProcess();
   RenderViewHost::FilterURL(render_process_host, false, &validated_url);
@@ -2280,7 +2280,7 @@ void WebContentsImpl::OnJSOutOfMemory() {
 
 void WebContentsImpl::OnRegisterProtocolHandler(const std::string& protocol,
                                                 const GURL& url,
-                                                const string16& title,
+                                                const base::string16& title,
                                                 bool user_gesture) {
   if (!delegate_)
     return;
@@ -2516,7 +2516,8 @@ void WebContentsImpl::SetIsLoading(RenderViewHost* render_view_host,
     return;
 
   if (!is_loading) {
-    load_state_ = net::LoadStateWithParam(net::LOAD_STATE_IDLE, string16());
+    load_state_ = net::LoadStateWithParam(net::LOAD_STATE_IDLE,
+                                          base::string16());
     load_state_host_.clear();
     upload_size_ = 0;
     upload_position_ = 0;
@@ -2618,11 +2619,11 @@ void WebContentsImpl::UpdateMaxPageIDIfNecessary(RenderViewHost* rvh) {
 }
 
 bool WebContentsImpl::UpdateTitleForEntry(NavigationEntryImpl* entry,
-                                          const string16& title) {
+                                          const base::string16& title) {
   // For file URLs without a title, use the pathname instead. In the case of a
   // synthesized title, we don't want the update to count toward the "one set
   // per page of the title to history."
-  string16 final_title;
+  base::string16 final_title;
   bool explicit_set;
   if (entry && entry->GetURL().SchemeIsFile() && title.empty()) {
     final_title = UTF8ToUTF16(entry->GetURL().ExtractFileName());
@@ -2975,7 +2976,7 @@ void WebContentsImpl::UpdateState(RenderViewHost* rvh,
 
 void WebContentsImpl::UpdateTitle(RenderViewHost* rvh,
                                   int32 page_id,
-                                  const string16& title,
+                                  const base::string16& title,
                                   base::i18n::TextDirection title_direction) {
   // If we have a title, that's a pretty good indication that we've started
   // getting useful data.
@@ -3291,8 +3292,8 @@ void WebContentsImpl::RouteMessageEvent(
 
 void WebContentsImpl::RunJavaScriptMessage(
     RenderViewHost* rvh,
-    const string16& message,
-    const string16& default_prompt,
+    const base::string16& message,
+    const base::string16& default_prompt,
     const GURL& frame_url,
     JavaScriptMessageType javascript_message_type,
     IPC::Message* reply_msg,
@@ -3330,7 +3331,7 @@ void WebContentsImpl::RunJavaScriptMessage(
   if (suppress_this_message) {
     // If we are suppressing messages, just reply as if the user immediately
     // pressed "Cancel".
-    OnDialogClosed(rvh, reply_msg, false, string16());
+    OnDialogClosed(rvh, reply_msg, false, base::string16());
   }
 
   // OnDialogClosed (two lines up) may have caused deletion of this object (see
@@ -3338,7 +3339,7 @@ void WebContentsImpl::RunJavaScriptMessage(
 }
 
 void WebContentsImpl::RunBeforeUnloadConfirm(RenderViewHost* rvh,
-                                             const string16& message,
+                                             const base::string16& message,
                                              bool is_reload,
                                              IPC::Message* reply_msg) {
   RenderViewHostImpl* rvhi = static_cast<RenderViewHostImpl*>(rvh);
@@ -3352,7 +3353,7 @@ void WebContentsImpl::RunBeforeUnloadConfirm(RenderViewHost* rvh,
       !delegate_->GetJavaScriptDialogManager();
   if (suppress_this_message) {
     // The reply must be sent to the RVH that sent the request.
-    rvhi->JavaScriptDialogClosed(reply_msg, true, string16());
+    rvhi->JavaScriptDialogClosed(reply_msg, true, base::string16());
     return;
   }
 
@@ -3365,9 +3366,9 @@ void WebContentsImpl::RunBeforeUnloadConfirm(RenderViewHost* rvh,
 }
 
 bool WebContentsImpl::AddMessageToConsole(int32 level,
-                                          const string16& message,
+                                          const base::string16& message,
                                           int32 line_no,
-                                          const string16& source_id) {
+                                          const base::string16& source_id) {
   if (!delegate_)
     return false;
   return delegate_->AddMessageToConsole(this, level, message, line_no,
@@ -3590,7 +3591,7 @@ bool WebContentsImpl::CreateRenderViewForRenderManager(
       GetMaxPageIDForSiteInstance(render_view_host->GetSiteInstance());
 
   if (!static_cast<RenderViewHostImpl*>(
-          render_view_host)->CreateRenderView(string16(),
+          render_view_host)->CreateRenderView(base::string16(),
                                               opener_route_id,
                                               max_page_id)) {
     return false;
@@ -3618,7 +3619,7 @@ bool WebContentsImpl::CreateRenderViewForInitialEmptyDocument() {
 void WebContentsImpl::OnDialogClosed(RenderViewHost* rvh,
                                      IPC::Message* reply_msg,
                                      bool success,
-                                     const string16& user_input) {
+                                     const base::string16& user_input) {
   if (is_showing_before_unload_dialog_ && !success) {
     // If a beforeunload dialog is canceled, we need to stop the throbber from
     // spinning, since we forced it to start spinning in Navigate.
diff --git a/content/browser/web_contents/web_contents_impl.h b/content/browser/web_contents/web_contents_impl.h
index 7229682..d2c0483 100644
--- a/content/browser/web_contents/web_contents_impl.h
+++ b/content/browser/web_contents/web_contents_impl.h
@@ -193,7 +193,7 @@ class CONTENT_EXPORT WebContentsImpl
   virtual void SetParentNativeViewAccessible(
       gfx::NativeViewAccessible accessible_parent) OVERRIDE;
 #endif
-  virtual const string16& GetTitle() const OVERRIDE;
+  virtual const base::string16& GetTitle() const OVERRIDE;
   virtual int32 GetMaxPageID() OVERRIDE;
   virtual int32 GetMaxPageIDForSiteInstance(
       SiteInstance* site_instance) OVERRIDE;
@@ -202,7 +202,7 @@ class CONTENT_EXPORT WebContentsImpl
   virtual bool IsLoading() const OVERRIDE;
   virtual bool IsWaitingForResponse() const OVERRIDE;
   virtual const net::LoadStateWithParam& GetLoadState() const OVERRIDE;
-  virtual const string16& GetLoadStateHost() const OVERRIDE;
+  virtual const base::string16& GetLoadStateHost() const OVERRIDE;
   virtual uint64 GetUploadSize() const OVERRIDE;
   virtual uint64 GetUploadPosition() const OVERRIDE;
   virtual std::set<GURL> GetSitesInTab() const OVERRIDE;
@@ -318,7 +318,7 @@ class CONTENT_EXPORT WebContentsImpl
                            const PageState& page_state) OVERRIDE;
   virtual void UpdateTitle(RenderViewHost* render_view_host,
                            int32 page_id,
-                           const string16& title,
+                           const base::string16& title,
                            base::i18n::TextDirection title_direction) OVERRIDE;
   virtual void UpdateEncoding(RenderViewHost* render_view_host,
                               const std::string& encoding) OVERRIDE;
@@ -359,20 +359,20 @@ class CONTENT_EXPORT WebContentsImpl
       RenderViewHost* rvh,
       const ViewMsg_PostMessage_Params& params) OVERRIDE;
   virtual void RunJavaScriptMessage(RenderViewHost* rvh,
-                                    const string16& message,
-                                    const string16& default_prompt,
+                                    const base::string16& message,
+                                    const base::string16& default_prompt,
                                     const GURL& frame_url,
                                     JavaScriptMessageType type,
                                     IPC::Message* reply_msg,
                                     bool* did_suppress_message) OVERRIDE;
   virtual void RunBeforeUnloadConfirm(RenderViewHost* rvh,
-                                      const string16& message,
+                                      const base::string16& message,
                                       bool is_reload,
                                       IPC::Message* reply_msg) OVERRIDE;
   virtual bool AddMessageToConsole(int32 level,
-                                   const string16& message,
+                                   const base::string16& message,
                                    int32 line_no,
-                                   const string16& source_id) OVERRIDE;
+                                   const base::string16& source_id) OVERRIDE;
   virtual RendererPreferences GetRendererPrefs(
       BrowserContext* browser_context) const OVERRIDE;
   virtual WebPreferences GetWebkitPrefs() OVERRIDE;
@@ -594,7 +594,7 @@ class CONTENT_EXPORT WebContentsImpl
   void OnDialogClosed(RenderViewHost* rvh,
                       IPC::Message* reply_msg,
                       bool success,
-                      const string16& user_input);
+                      const base::string16& user_input);
 
   // Callback function when requesting permission to access the PPAPI broker.
   // |result| is true if permission was granted.
@@ -617,7 +617,7 @@ class CONTENT_EXPORT WebContentsImpl
                               const GURL& url,
                               bool is_main_frame,
                               int error_code,
-                              const string16& error_description);
+                              const base::string16& error_description);
   void OnGoToEntryAtOffset(int offset);
   void OnUpdateZoomLimits(int minimum_percent,
                           int maximum_percent,
@@ -627,7 +627,7 @@ class CONTENT_EXPORT WebContentsImpl
 
   void OnRegisterProtocolHandler(const std::string& protocol,
                                  const GURL& url,
-                                 const string16& title,
+                                 const base::string16& title,
                                  bool user_gesture);
   void OnFindReply(int request_id,
                    int number_of_matches,
@@ -714,7 +714,7 @@ class CONTENT_EXPORT WebContentsImpl
   // or the dedicated set title message. It returns true if the new title is
   // different and was therefore updated.
   bool UpdateTitleForEntry(NavigationEntryImpl* entry,
-                           const string16& title);
+                           const base::string16& title);
 
   // Causes the WebContentsImpl to navigate in the right renderer to |entry|,
   // which must be already part of the entries in the navigation controller.
@@ -876,7 +876,7 @@ class CONTENT_EXPORT WebContentsImpl
 
   // The current load state and the URL associated with it.
   net::LoadStateWithParam load_state_;
-  string16 load_state_host_;
+  base::string16 load_state_host_;
   // Upload progress, for displaying in the status bar.
   // Set to zero when there is no significant upload happening.
   uint64 upload_size_;
@@ -885,7 +885,7 @@ class CONTENT_EXPORT WebContentsImpl
   // Data for current page -----------------------------------------------------
 
   // When a title cannot be taken from any entry, this title will be used.
-  string16 page_title_when_no_navigation_entry_;
+  base::string16 page_title_when_no_navigation_entry_;
 
   // When a navigation occurs, we record its contents MIME type. It can be
   // used to check whether we can do something for some special contents.
diff --git a/content/browser/web_contents/web_contents_impl_unittest.cc b/content/browser/web_contents/web_contents_impl_unittest.cc
index d5ac705..01c0191 100644
--- a/content/browser/web_contents/web_contents_impl_unittest.cc
+++ b/content/browser/web_contents/web_contents_impl_unittest.cc
@@ -284,7 +284,7 @@ class TestWebContentsObserver : public WebContentsObserver {
                            const GURL& validated_url,
                            bool is_main_frame,
                            int error_code,
-                           const string16& error_description,
+                           const base::string16& error_description,
                            RenderViewHost* render_view_host) OVERRIDE {
     last_url_ = validated_url;
   }
@@ -318,12 +318,12 @@ TEST_F(WebContentsImplTest, DontUseTitleFromPendingEntry) {
   const GURL kGURL("chrome://blah");
   controller().LoadURL(
       kGURL, Referrer(), PAGE_TRANSITION_TYPED, std::string());
-  EXPECT_EQ(string16(), contents()->GetTitle());
+  EXPECT_EQ(base::string16(), contents()->GetTitle());
 }
 
 TEST_F(WebContentsImplTest, UseTitleFromPendingEntryIfSet) {
   const GURL kGURL("chrome://blah");
-  const string16 title = ASCIIToUTF16("My Title");
+  const base::string16 title = ASCIIToUTF16("My Title");
   controller().LoadURL(
       kGURL, Referrer(), PAGE_TRANSITION_TYPED, std::string());
 
@@ -2152,7 +2152,7 @@ TEST_F(WebContentsImplTest, FilterURLs) {
 
   // Check that an IPC with about:whatever is correctly normalized.
   other_contents->TestDidFailLoadWithError(
-      1, url_from_ipc, true, 1, string16());
+      1, url_from_ipc, true, 1, base::string16());
   EXPECT_EQ(url_normalized, other_observer.last_url());
 }
 
diff --git a/content/browser/web_contents/web_contents_view_android.cc b/content/browser/web_contents/web_contents_view_android.cc
index fc27ace..f66b5ec 100644
--- a/content/browser/web_contents/web_contents_view_android.cc
+++ b/content/browser/web_contents/web_contents_view_android.cc
@@ -80,7 +80,7 @@ void WebContentsViewAndroid::GetContainerBounds(gfx::Rect* out) const {
     *out = rwhv->GetViewBounds();
 }
 
-void WebContentsViewAndroid::SetPageTitle(const string16& title) {
+void WebContentsViewAndroid::SetPageTitle(const base::string16& title) {
   if (content_view_core_)
     content_view_core_->SetTitle(title);
 }
diff --git a/content/browser/web_contents/web_contents_view_android.h b/content/browser/web_contents/web_contents_view_android.h
index bcfc0cf..849ca6d 100644
--- a/content/browser/web_contents/web_contents_view_android.h
+++ b/content/browser/web_contents/web_contents_view_android.h
@@ -57,7 +57,7 @@ class WebContentsViewAndroid : public WebContentsViewPort,
       RenderWidgetHost* render_widget_host) OVERRIDE;
   virtual RenderWidgetHostView* CreateViewForPopupWidget(
       RenderWidgetHost* render_widget_host) OVERRIDE;
-  virtual void SetPageTitle(const string16& title) OVERRIDE;
+  virtual void SetPageTitle(const base::string16& title) OVERRIDE;
   virtual void RenderViewCreated(RenderViewHost* host) OVERRIDE;
   virtual void RenderViewSwappedIn(RenderViewHost* host) OVERRIDE;
   virtual void SetOverscrollControllerEnabled(bool enabled) OVERRIDE;
diff --git a/content/browser/web_contents/web_contents_view_aura.cc b/content/browser/web_contents/web_contents_view_aura.cc
index 353da78..75ca4e6 100644
--- a/content/browser/web_contents/web_contents_view_aura.cc
+++ b/content/browser/web_contents/web_contents_view_aura.cc
@@ -249,7 +249,7 @@ void PrepareDragForFileContents(const DropData& drop_data,
   // Images without ALT text will only have a file extension so we need to
   // synthesize one from the provided extension and URL.
   if (file_name.BaseName().RemoveExtension().empty()) {
-    const string16 extension = file_name.Extension();
+    const base::string16 extension = file_name.Extension();
     // Retrieve the name from the URL.
     file_name = base::FilePath(net::GetSuggestedFilename(
         drop_data.url, "", "", "", "", "")).ReplaceExtension(extension);
@@ -296,20 +296,20 @@ void PrepareDragData(const DropData& drop_data,
 
 // Utility to fill a DropData object from ui::OSExchangeData.
 void PrepareDropData(DropData* drop_data, const ui::OSExchangeData& data) {
-  string16 plain_text;
+  base::string16 plain_text;
   data.GetString(&plain_text);
   if (!plain_text.empty())
     drop_data->text = base::NullableString16(plain_text, false);
 
   GURL url;
-  string16 url_title;
+  base::string16 url_title;
   data.GetURLAndTitle(&url, &url_title);
   if (url.is_valid()) {
     drop_data->url = url;
     drop_data->url_title = url_title;
   }
 
-  string16 html;
+  base::string16 html;
   GURL html_base_url;
   data.GetHtml(&html, &html_base_url);
   if (!html.empty())
@@ -1298,7 +1298,7 @@ RenderWidgetHostView* WebContentsViewAura::CreateViewForPopupWidget(
   return RenderWidgetHostViewPort::CreateViewForWidget(render_widget_host);
 }
 
-void WebContentsViewAura::SetPageTitle(const string16& title) {
+void WebContentsViewAura::SetPageTitle(const base::string16& title) {
   window_->set_title(title);
 }
 
diff --git a/content/browser/web_contents/web_contents_view_aura.h b/content/browser/web_contents/web_contents_view_aura.h
index 7d377b0..a0597d3 100644
--- a/content/browser/web_contents/web_contents_view_aura.h
+++ b/content/browser/web_contents/web_contents_view_aura.h
@@ -118,7 +118,7 @@ class CONTENT_EXPORT WebContentsViewAura
       RenderWidgetHost* render_widget_host) OVERRIDE;
   virtual RenderWidgetHostView* CreateViewForPopupWidget(
       RenderWidgetHost* render_widget_host) OVERRIDE;
-  virtual void SetPageTitle(const string16& title) OVERRIDE;
+  virtual void SetPageTitle(const base::string16& title) OVERRIDE;
   virtual void RenderViewCreated(RenderViewHost* host) OVERRIDE;
   virtual void RenderViewSwappedIn(RenderViewHost* host) OVERRIDE;
   virtual void SetOverscrollControllerEnabled(bool enabled) OVERRIDE;
diff --git a/content/browser/web_contents/web_contents_view_aura_browsertest.cc b/content/browser/web_contents/web_contents_view_aura_browsertest.cc
index 3214c13..687ce57 100644
--- a/content/browser/web_contents/web_contents_view_aura_browsertest.cc
+++ b/content/browser/web_contents/web_contents_view_aura_browsertest.cc
@@ -196,14 +196,14 @@ class WebContentsViewAuraTest : public ContentBrowserTest {
 
     {
       // Do a swipe-right now. That should navigate backwards.
-      string16 expected_title = ASCIIToUTF16("Title: #1");
+      base::string16 expected_title = ASCIIToUTF16("Title: #1");
       content::TitleWatcher title_watcher(web_contents, expected_title);
       generator.GestureScrollSequence(
           gfx::Point(bounds.x() + 2, bounds.y() + 10),
           gfx::Point(bounds.right() - 10, bounds.y() + 10),
           base::TimeDelta::FromMilliseconds(kScrollDurationMs),
           kScrollSteps);
-      string16 actual_title = title_watcher.WaitAndGetTitle();
+      base::string16 actual_title = title_watcher.WaitAndGetTitle();
       EXPECT_EQ(expected_title, actual_title);
       value = content::ExecuteScriptAndGetValue(view_host, "get_current()");
       ASSERT_TRUE(value->GetAsInteger(&index));
@@ -214,14 +214,14 @@ class WebContentsViewAuraTest : public ContentBrowserTest {
 
     {
       // Do a fling-right now. That should navigate backwards.
-      string16 expected_title = ASCIIToUTF16("Title:");
+      base::string16 expected_title = ASCIIToUTF16("Title:");
       content::TitleWatcher title_watcher(web_contents, expected_title);
       generator.GestureScrollSequence(
           gfx::Point(bounds.x() + 2, bounds.y() + 10),
           gfx::Point(bounds.right() - 10, bounds.y() + 10),
           base::TimeDelta::FromMilliseconds(kScrollDurationMs),
           kScrollSteps);
-      string16 actual_title = title_watcher.WaitAndGetTitle();
+      base::string16 actual_title = title_watcher.WaitAndGetTitle();
       EXPECT_EQ(expected_title, actual_title);
       value = content::ExecuteScriptAndGetValue(view_host, "get_current()");
       ASSERT_TRUE(value->GetAsInteger(&index));
@@ -232,14 +232,14 @@ class WebContentsViewAuraTest : public ContentBrowserTest {
 
     {
       // Do a swipe-left now. That should navigate forward.
-      string16 expected_title = ASCIIToUTF16("Title: #1");
+      base::string16 expected_title = ASCIIToUTF16("Title: #1");
       content::TitleWatcher title_watcher(web_contents, expected_title);
       generator.GestureScrollSequence(
           gfx::Point(bounds.right() - 10, bounds.y() + 10),
           gfx::Point(bounds.x() + 2, bounds.y() + 10),
           base::TimeDelta::FromMilliseconds(kScrollDurationMs),
           kScrollSteps);
-      string16 actual_title = title_watcher.WaitAndGetTitle();
+      base::string16 actual_title = title_watcher.WaitAndGetTitle();
       EXPECT_EQ(expected_title, actual_title);
       value = content::ExecuteScriptAndGetValue(view_host, "get_current()");
       ASSERT_TRUE(value->GetAsInteger(&index));
@@ -438,7 +438,7 @@ IN_PROC_BROWSER_TEST_F(WebContentsViewAuraTest, OverscrollScreenshot) {
   {
     // Now, swipe right to navigate backwards. This should navigate away from
     // index 3 to index 2, and index 3 should have a screenshot.
-    string16 expected_title = ASCIIToUTF16("Title: #2");
+    base::string16 expected_title = ASCIIToUTF16("Title: #2");
     content::TitleWatcher title_watcher(web_contents, expected_title);
     aura::Window* content = web_contents->GetView()->GetContentNativeView();
     gfx::Rect bounds = content->GetBoundsInRootWindow();
@@ -448,7 +448,7 @@ IN_PROC_BROWSER_TEST_F(WebContentsViewAuraTest, OverscrollScreenshot) {
         gfx::Point(bounds.right() - 10, bounds.y() + 10),
         base::TimeDelta::FromMilliseconds(20),
         1);
-    string16 actual_title = title_watcher.WaitAndGetTitle();
+    base::string16 actual_title = title_watcher.WaitAndGetTitle();
     EXPECT_EQ(expected_title, actual_title);
     EXPECT_EQ(2, GetCurrentIndex());
     screenshot_manager()->WaitUntilScreenshotIsReady();
@@ -469,10 +469,10 @@ IN_PROC_BROWSER_TEST_F(WebContentsViewAuraTest, OverscrollScreenshot) {
 
   {
     // Navigate back in history.
-    string16 expected_title = ASCIIToUTF16("Title: #3");
+    base::string16 expected_title = ASCIIToUTF16("Title: #3");
     content::TitleWatcher title_watcher(web_contents, expected_title);
     web_contents->GetController().GoBack();
-    string16 actual_title = title_watcher.WaitAndGetTitle();
+    base::string16 actual_title = title_watcher.WaitAndGetTitle();
     EXPECT_EQ(expected_title, actual_title);
     EXPECT_EQ(3, GetCurrentIndex());
     screenshot_manager()->WaitUntilScreenshotIsReady();
@@ -641,7 +641,7 @@ IN_PROC_BROWSER_TEST_F(WebContentsViewAuraTest,
 
   // Do a swipe left to start a forward navigation. Then quickly do a swipe
   // right.
-  string16 expected_title = ASCIIToUTF16("Title: #2");
+  base::string16 expected_title = ASCIIToUTF16("Title: #2");
   content::TitleWatcher title_watcher(web_contents, expected_title);
   NavigationWatcher nav_watcher(web_contents);
 
@@ -657,7 +657,7 @@ IN_PROC_BROWSER_TEST_F(WebContentsViewAuraTest,
       gfx::Point(bounds.right() - 10, bounds.y() + 10),
       base::TimeDelta::FromMilliseconds(2000),
       10);
-  string16 actual_title = title_watcher.WaitAndGetTitle();
+  base::string16 actual_title = title_watcher.WaitAndGetTitle();
   EXPECT_EQ(expected_title, actual_title);
 
   EXPECT_EQ(2, GetCurrentIndex());
diff --git a/content/browser/web_contents/web_contents_view_gtk.cc b/content/browser/web_contents/web_contents_view_gtk.cc
index 4e3874f..bf4dcb7f 100644
--- a/content/browser/web_contents/web_contents_view_gtk.cc
+++ b/content/browser/web_contents/web_contents_view_gtk.cc
@@ -246,7 +246,7 @@ RenderWidgetHostView* WebContentsViewGtk::CreateViewForPopupWidget(
   return RenderWidgetHostViewPort::CreateViewForWidget(render_widget_host);
 }
 
-void WebContentsViewGtk::SetPageTitle(const string16& title) {
+void WebContentsViewGtk::SetPageTitle(const base::string16& title) {
   // Set the window name to include the page title so it's easier to spot
   // when debugging (e.g. via xwininfo -tree).
   gfx::NativeView content_view = GetContentNativeView();
diff --git a/content/browser/web_contents/web_contents_view_gtk.h b/content/browser/web_contents/web_contents_view_gtk.h
index 41f84ab..7a8d25e 100644
--- a/content/browser/web_contents/web_contents_view_gtk.h
+++ b/content/browser/web_contents/web_contents_view_gtk.h
@@ -66,7 +66,7 @@ class CONTENT_EXPORT WebContentsViewGtk
       RenderWidgetHost* render_widget_host) OVERRIDE;
   virtual RenderWidgetHostView* CreateViewForPopupWidget(
       RenderWidgetHost* render_widget_host) OVERRIDE;
-  virtual void SetPageTitle(const string16& title) OVERRIDE;
+  virtual void SetPageTitle(const base::string16& title) OVERRIDE;
   virtual void RenderViewCreated(RenderViewHost* host) OVERRIDE;
   virtual void RenderViewSwappedIn(RenderViewHost* host) OVERRIDE;
   virtual void SetOverscrollControllerEnabled(bool enabled) OVERRIDE;
diff --git a/content/browser/web_contents/web_contents_view_guest.cc b/content/browser/web_contents/web_contents_view_guest.cc
index ac236da..90296a9 100644
--- a/content/browser/web_contents/web_contents_view_guest.cc
+++ b/content/browser/web_contents/web_contents_view_guest.cc
@@ -142,7 +142,7 @@ RenderWidgetHostView* WebContentsViewGuest::CreateViewForPopupWidget(
   return RenderWidgetHostViewPort::CreateViewForWidget(render_widget_host);
 }
 
-void WebContentsViewGuest::SetPageTitle(const string16& title) {
+void WebContentsViewGuest::SetPageTitle(const base::string16& title) {
 }
 
 void WebContentsViewGuest::RenderViewCreated(RenderViewHost* host) {
diff --git a/content/browser/web_contents/web_contents_view_guest.h b/content/browser/web_contents/web_contents_view_guest.h
index 1e1d812..976a04e 100644
--- a/content/browser/web_contents/web_contents_view_guest.h
+++ b/content/browser/web_contents/web_contents_view_guest.h
@@ -65,7 +65,7 @@ class CONTENT_EXPORT WebContentsViewGuest
       RenderWidgetHost* render_widget_host) OVERRIDE;
   virtual RenderWidgetHostView* CreateViewForPopupWidget(
       RenderWidgetHost* render_widget_host) OVERRIDE;
-  virtual void SetPageTitle(const string16& title) OVERRIDE;
+  virtual void SetPageTitle(const base::string16& title) OVERRIDE;
   virtual void RenderViewCreated(RenderViewHost* host) OVERRIDE;
   virtual void RenderViewSwappedIn(RenderViewHost* host) OVERRIDE;
   virtual void SetOverscrollControllerEnabled(bool enabled) OVERRIDE;
diff --git a/content/browser/web_contents/web_contents_view_mac.h b/content/browser/web_contents/web_contents_view_mac.h
index 3d0b94f..a8ffab4 100644
--- a/content/browser/web_contents/web_contents_view_mac.h
+++ b/content/browser/web_contents/web_contents_view_mac.h
@@ -88,7 +88,7 @@ class WebContentsViewMac : public WebContentsViewPort,
       RenderWidgetHost* render_widget_host) OVERRIDE;
   virtual RenderWidgetHostView* CreateViewForPopupWidget(
       RenderWidgetHost* render_widget_host) OVERRIDE;
-  virtual void SetPageTitle(const string16& title) OVERRIDE;
+  virtual void SetPageTitle(const base::string16& title) OVERRIDE;
   virtual void RenderViewCreated(RenderViewHost* host) OVERRIDE;
   virtual void RenderViewSwappedIn(RenderViewHost* host) OVERRIDE;
   virtual void SetOverscrollControllerEnabled(bool enabled) OVERRIDE;
diff --git a/content/browser/web_contents/web_contents_view_mac.mm b/content/browser/web_contents/web_contents_view_mac.mm
index 4283ca9..e80bf99 100644
--- a/content/browser/web_contents/web_contents_view_mac.mm
+++ b/content/browser/web_contents/web_contents_view_mac.mm
@@ -332,7 +332,7 @@ RenderWidgetHostView* WebContentsViewMac::CreateViewForPopupWidget(
   return RenderWidgetHostViewPort::CreateViewForWidget(render_widget_host);
 }
 
-void WebContentsViewMac::SetPageTitle(const string16& title) {
+void WebContentsViewMac::SetPageTitle(const base::string16& title) {
   // Meaningless on the Mac; widgets don't have a "title" attribute
 }
 
diff --git a/content/browser/web_contents/web_contents_view_win.cc b/content/browser/web_contents/web_contents_view_win.cc
index 92548d2..8360d8c 100644
--- a/content/browser/web_contents/web_contents_view_win.cc
+++ b/content/browser/web_contents/web_contents_view_win.cc
@@ -228,7 +228,7 @@ RenderWidgetHostView* WebContentsViewWin::CreateViewForPopupWidget(
   return RenderWidgetHostViewPort::CreateViewForWidget(render_widget_host);
 }
 
-void WebContentsViewWin::SetPageTitle(const string16& title) {
+void WebContentsViewWin::SetPageTitle(const base::string16& title) {
   // It's possible to get this after the hwnd has been destroyed.
   if (GetNativeView())
     ::SetWindowText(GetNativeView(), title.c_str());
diff --git a/content/browser/web_contents/web_contents_view_win.h b/content/browser/web_contents/web_contents_view_win.h
index 505addd..9b052e2 100644
--- a/content/browser/web_contents/web_contents_view_win.h
+++ b/content/browser/web_contents/web_contents_view_win.h
@@ -73,7 +73,7 @@ class CONTENT_EXPORT WebContentsViewWin
       RenderWidgetHost* render_widget_host) OVERRIDE;
   virtual RenderWidgetHostView* CreateViewForPopupWidget(
       RenderWidgetHost* render_widget_host) OVERRIDE;
-  virtual void SetPageTitle(const string16& title) OVERRIDE;
+  virtual void SetPageTitle(const base::string16& title) OVERRIDE;
   virtual void RenderViewCreated(RenderViewHost* host) OVERRIDE;
   virtual void RenderViewSwappedIn(RenderViewHost* host) OVERRIDE;
   virtual void SetOverscrollControllerEnabled(bool enabled) OVERRIDE;
diff --git a/content/browser/web_contents/web_drag_dest_gtk.cc b/content/browser/web_contents/web_drag_dest_gtk.cc
index bb9a4d4..738d6b5 100644
--- a/content/browser/web_contents/web_drag_dest_gtk.cc
+++ b/content/browser/web_contents/web_drag_dest_gtk.cc
@@ -204,7 +204,8 @@ void WebDragDestGtk::OnDragDataReceived(
           if (url.SchemeIs(chrome::kFileScheme) &&
               net::FileURLToFilePath(url, &file_path)) {
             drop_data_->filenames.push_back(
-                DropData::FileInfo(UTF8ToUTF16(file_path.value()), string16()));
+                DropData::FileInfo(UTF8ToUTF16(file_path.value()),
+                                   base::string16()));
             // This is a hack. Some file managers also populate text/plain with
             // a file URL when dragging files, so we clear it to avoid exposing
             // it to the web content.
diff --git a/content/browser/web_contents/web_drag_dest_mac.mm b/content/browser/web_contents/web_drag_dest_mac.mm
index b3fefca..8768bed 100644
--- a/content/browser/web_contents/web_drag_dest_mac.mm
+++ b/content/browser/web_contents/web_drag_dest_mac.mm
@@ -290,7 +290,7 @@ int GetModifierFlags() {
         if (exists) {
           data->filenames.push_back(
               DropData::FileInfo(
-                  base::SysNSStringToUTF16(filename), string16()));
+                  base::SysNSStringToUTF16(filename), base::string16()));
         }
       }
     }
diff --git a/content/browser/web_contents/web_drag_dest_mac_unittest.mm b/content/browser/web_contents/web_drag_dest_mac_unittest.mm
index 48719de..b79c118 100644
--- a/content/browser/web_contents/web_drag_dest_mac_unittest.mm
+++ b/content/browser/web_contents/web_drag_dest_mac_unittest.mm
@@ -85,7 +85,7 @@ TEST_F(WebDragDestTest, URL) {
   NSString* url = nil;
   NSString* title = nil;
   GURL result_url;
-  string16 result_title;
+  base::string16 result_title;
 
   // Put a URL on the pasteboard and check it.
   pboard = [NSPasteboard pasteboardWithUniqueName];
diff --git a/content/browser/web_contents/web_drag_source_gtk.h b/content/browser/web_contents/web_drag_source_gtk.h
index 577f60b..8a7c7b2 100644
--- a/content/browser/web_contents/web_drag_source_gtk.h
+++ b/content/browser/web_contents/web_drag_source_gtk.h
@@ -92,7 +92,7 @@ class CONTENT_EXPORT WebDragSourceGtk :
   GdkDragContext* drag_context_;
 
   // The file mime type for a drag-out download.
-  string16 wide_download_mime_type_;
+  base::string16 wide_download_mime_type_;
 
   // The file name to be saved to for a drag-out download.
   base::FilePath download_file_name_;
diff --git a/content/browser/web_contents/web_drag_source_mac.mm b/content/browser/web_contents/web_drag_source_mac.mm
index 805e73b..c667320 100644
--- a/content/browser/web_contents/web_drag_source_mac.mm
+++ b/content/browser/web_contents/web_drag_source_mac.mm
@@ -49,10 +49,10 @@ namespace {
 // |NSURLPboardType|.
 NSString* const kNSURLTitlePboardType = @"public.url-name";
 
-// Converts a string16 into a FilePath. Use this method instead of
+// Converts a base::string16 into a FilePath. Use this method instead of
 // -[NSString fileSystemRepresentation] to prevent exceptions from being thrown.
 // See http://crbug.com/78782 for more info.
-base::FilePath FilePathFromFilename(const string16& filename) {
+base::FilePath FilePathFromFilename(const base::string16& filename) {
   NSString* str = SysUTF16ToNSString(filename);
   char buf[MAXPATHLEN];
   if (![str getFileSystemRepresentation:buf maxLength:sizeof(buf)])
@@ -71,7 +71,7 @@ base::FilePath GetFileNameFromDragData(const DropData& drop_data) {
   // synthesize one from the provided extension and URL.
   if (file_name.empty()) {
     // Retrieve the name from the URL.
-    string16 suggested_filename =
+    base::string16 suggested_filename =
         net::GetSuggestedFilename(drop_data.url, "", "", "", "", "");
     const std::string extension = file_name.Extension();
     file_name = FilePathFromFilename(suggested_filename);
@@ -147,7 +147,7 @@ void PromiseWriterHelper(const DropData& drop_data,
 - (void)lazyWriteToPasteboard:(NSPasteboard*)pboard forType:(NSString*)type {
   // NSHTMLPboardType requires the character set to be declared. Otherwise, it
   // assumes US-ASCII. Awesome.
-  const string16 kHtmlHeader = ASCIIToUTF16(
+  const base::string16 kHtmlHeader = ASCIIToUTF16(
       "<meta http-equiv=\"Content-Type\" content=\"text/html;charset=UTF-8\">");
 
   // Be extra paranoid; avoid crashing.
@@ -386,7 +386,7 @@ void PromiseWriterHelper(const DropData& drop_data,
       downloadFileName_ = GetFileNameFromDragData(*dropData_);
       net::GetMimeTypeFromExtension(downloadFileName_.Extension(), &mimeType);
     } else {
-      string16 mimeType16;
+      base::string16 mimeType16;
       base::FilePath fileName;
       if (content::ParseDownloadMetadata(
               dropData_->download_metadata,
diff --git a/content/browser/webui/web_ui_data_source_impl.cc b/content/browser/webui/web_ui_data_source_impl.cc
index 6a5b6025..6775eb7 100644
--- a/content/browser/webui/web_ui_data_source_impl.cc
+++ b/content/browser/webui/web_ui_data_source_impl.cc
@@ -95,7 +95,7 @@ WebUIDataSourceImpl::~WebUIDataSourceImpl() {
 }
 
 void WebUIDataSourceImpl::AddString(const std::string& name,
-                                    const string16& value) {
+                                    const base::string16& value) {
   localized_strings_.SetString(name, value);
 }
 
diff --git a/content/browser/webui/web_ui_data_source_impl.h b/content/browser/webui/web_ui_data_source_impl.h
index 1f81004..91ec087 100644
--- a/content/browser/webui/web_ui_data_source_impl.h
+++ b/content/browser/webui/web_ui_data_source_impl.h
@@ -28,7 +28,7 @@ class CONTENT_EXPORT WebUIDataSourceImpl
  public:
   // WebUIDataSource implementation:
   virtual void AddString(const std::string& name,
-                         const string16& value) OVERRIDE;
+                         const base::string16& value) OVERRIDE;
   virtual void AddString(const std::string& name,
                          const std::string& value) OVERRIDE;
   virtual void AddLocalizedString(const std::string& name, int ids) OVERRIDE;
diff --git a/content/browser/webui/web_ui_data_source_unittest.cc b/content/browser/webui/web_ui_data_source_unittest.cc
index f384a43..a5da7eb 100644
--- a/content/browser/webui/web_ui_data_source_unittest.cc
+++ b/content/browser/webui/web_ui_data_source_unittest.cc
@@ -25,10 +25,10 @@ class TestClient : public TestContentClient {
   TestClient() {}
   virtual ~TestClient() {}
 
-  virtual string16 GetLocalizedString(int message_id) const OVERRIDE {
+  virtual base::string16 GetLocalizedString(int message_id) const OVERRIDE {
     if (message_id == kDummyStringId)
       return UTF8ToUTF16(kDummyString);
-    return string16();
+    return base::string16();
 
   }
 
diff --git a/content/browser/webui/web_ui_impl.cc b/content/browser/webui/web_ui_impl.cc
index e54a6d8..4774e4f 100644
--- a/content/browser/webui/web_ui_impl.cc
+++ b/content/browser/webui/web_ui_impl.cc
@@ -27,10 +27,10 @@ namespace content {
 const WebUI::TypeID WebUI::kNoWebUI = NULL;
 
 // static
-string16 WebUI::GetJavascriptCall(
+base::string16 WebUI::GetJavascriptCall(
     const std::string& function_name,
     const std::vector<const Value*>& arg_list) {
-  string16 parameters;
+  base::string16 parameters;
   std::string json;
   for (size_t i = 0; i < arg_list.size(); ++i) {
     if (i > 0)
@@ -106,11 +106,11 @@ ui::ScaleFactor WebUIImpl::GetDeviceScaleFactor() const {
   return GetScaleFactorForView(web_contents_->GetRenderWidgetHostView());
 }
 
-const string16& WebUIImpl::GetOverriddenTitle() const {
+const base::string16& WebUIImpl::GetOverriddenTitle() const {
   return overridden_title_;
 }
 
-void WebUIImpl::OverrideTitle(const string16& title) {
+void WebUIImpl::OverrideTitle(const base::string16& title) {
   overridden_title_ = title;
 }
 
@@ -144,7 +144,7 @@ void WebUIImpl::SetController(WebUIController* controller) {
 
 void WebUIImpl::CallJavascriptFunction(const std::string& function_name) {
   DCHECK(IsStringASCII(function_name));
-  string16 javascript = ASCIIToUTF16(function_name + "();");
+  base::string16 javascript = ASCIIToUTF16(function_name + "();");
   ExecuteJavascript(javascript);
 }
 
@@ -230,7 +230,7 @@ void WebUIImpl::AddMessageHandler(WebUIMessageHandler* handler) {
   handlers_.push_back(handler);
 }
 
-void WebUIImpl::ExecuteJavascript(const string16& javascript) {
+void WebUIImpl::ExecuteJavascript(const base::string16& javascript) {
   static_cast<RenderViewHostImpl*>(
       web_contents_->GetRenderViewHost())->ExecuteJavascriptInWebFrame(
       ASCIIToUTF16(frame_xpath_), javascript);
diff --git a/content/browser/webui/web_ui_impl.h b/content/browser/webui/web_ui_impl.h
index a359117..8715e43 100644
--- a/content/browser/webui/web_ui_impl.h
+++ b/content/browser/webui/web_ui_impl.h
@@ -33,8 +33,8 @@ class CONTENT_EXPORT WebUIImpl : public WebUI,
   virtual WebUIController* GetController() const OVERRIDE;
   virtual void SetController(WebUIController* controller) OVERRIDE;
   virtual ui::ScaleFactor GetDeviceScaleFactor() const OVERRIDE;
-  virtual const string16& GetOverriddenTitle() const OVERRIDE;
-  virtual void OverrideTitle(const string16& title) OVERRIDE;
+  virtual const base::string16& GetOverriddenTitle() const OVERRIDE;
+  virtual void OverrideTitle(const base::string16& title) OVERRIDE;
   virtual PageTransition GetLinkTransitionType() const OVERRIDE;
   virtual void SetLinkTransitionType(PageTransition type) OVERRIDE;
   virtual int GetBindings() const OVERRIDE;
@@ -78,7 +78,7 @@ class CONTENT_EXPORT WebUIImpl : public WebUI,
                    const base::ListValue& args);
 
   // Execute a string of raw Javascript on the page.
-  void ExecuteJavascript(const string16& javascript);
+  void ExecuteJavascript(const base::string16& javascript);
 
   // A map of message name -> message handling callback.
   typedef std::map<std::string, MessageCallback> MessageCallbackMap;
@@ -86,7 +86,7 @@ class CONTENT_EXPORT WebUIImpl : public WebUI,
 
   // Options that may be overridden by individual Web UI implementations. The
   // bool options default to false. See the public getters for more information.
-  string16 overridden_title_;  // Defaults to empty string.
+  base::string16 overridden_title_;  // Defaults to empty string.
   PageTransition link_transition_type_;  // Defaults to LINK.
   int bindings_;  // The bindings from BindingsPolicy that should be enabled for
                   // this page.
diff --git a/content/browser/webui/web_ui_message_handler.cc b/content/browser/webui/web_ui_message_handler.cc
index db554c0e..57b2c46 100644
--- a/content/browser/webui/web_ui_message_handler.cc
+++ b/content/browser/webui/web_ui_message_handler.cc
@@ -36,12 +36,12 @@ bool WebUIMessageHandler::ExtractDoubleValue(const ListValue* value,
   return false;
 }
 
-string16 WebUIMessageHandler::ExtractStringValue(const ListValue* value) {
-  string16 string16_value;
+base::string16 WebUIMessageHandler::ExtractStringValue(const ListValue* value) {
+  base::string16 string16_value;
   if (value->GetString(0, &string16_value))
     return string16_value;
   NOTREACHED();
-  return string16();
+  return base::string16();
 }
 
 }  // namespace content
diff --git a/content/browser/webui/web_ui_message_handler_unittest.cc b/content/browser/webui/web_ui_message_handler_unittest.cc
index e38acd7..33cdb61 100644
--- a/content/browser/webui/web_ui_message_handler_unittest.cc
+++ b/content/browser/webui/web_ui_message_handler_unittest.cc
@@ -14,9 +14,9 @@ namespace content {
 TEST(WebUIMessageHandlerTest, ExtractIntegerValue) {
   ListValue list;
   int value, zero_value = 0, neg_value = -1234, pos_value = 1234;
-  string16 zero_string(UTF8ToUTF16("0"));
-  string16 neg_string(UTF8ToUTF16("-1234"));
-  string16 pos_string(UTF8ToUTF16("1234"));
+  base::string16 zero_string(UTF8ToUTF16("0"));
+  base::string16 neg_string(UTF8ToUTF16("-1234"));
+  base::string16 pos_string(UTF8ToUTF16("1234"));
 
   list.Append(new base::FundamentalValue(zero_value));
   EXPECT_TRUE(WebUIMessageHandler::ExtractIntegerValue(&list, &value));
@@ -51,9 +51,9 @@ TEST(WebUIMessageHandlerTest, ExtractIntegerValue) {
 TEST(WebUIMessageHandlerTest, ExtractDoubleValue) {
   base::ListValue list;
   double value, zero_value = 0.0, neg_value = -1234.5, pos_value = 1234.5;
-  string16 zero_string(UTF8ToUTF16("0"));
-  string16 neg_string(UTF8ToUTF16("-1234.5"));
-  string16 pos_string(UTF8ToUTF16("1234.5"));
+  base::string16 zero_string(UTF8ToUTF16("0"));
+  base::string16 neg_string(UTF8ToUTF16("-1234.5"));
+  base::string16 pos_string(UTF8ToUTF16("1234.5"));
 
   list.Append(new base::FundamentalValue(zero_value));
   EXPECT_TRUE(WebUIMessageHandler::ExtractDoubleValue(&list, &value));
@@ -87,10 +87,10 @@ TEST(WebUIMessageHandlerTest, ExtractDoubleValue) {
 
 TEST(WebUIMessageHandlerTest, ExtractStringValue) {
   base::ListValue list;
-  string16 in_string(UTF8ToUTF16(
+  base::string16 in_string(UTF8ToUTF16(
       "The facts, though interesting, are irrelevant."));
   list.Append(new base::StringValue(in_string));
-  string16 out_string = WebUIMessageHandler::ExtractStringValue(&list);
+  base::string16 out_string = WebUIMessageHandler::ExtractStringValue(&list);
   EXPECT_EQ(in_string, out_string);
 }
 
diff --git a/content/browser/worker_host/test/worker_browsertest.cc b/content/browser/worker_host/test/worker_browsertest.cc
index a71a28e..acd00fb 100644
--- a/content/browser/worker_host/test/worker_browsertest.cc
+++ b/content/browser/worker_host/test/worker_browsertest.cc
@@ -42,10 +42,10 @@ class WorkerTest : public ContentBrowserTest {
                const std::string& test_case,
                const std::string& query) {
     GURL url = GetTestURL(test_case, query);
-    const string16 expected_title = ASCIIToUTF16("OK");
+    const base::string16 expected_title = ASCIIToUTF16("OK");
     TitleWatcher title_watcher(window->web_contents(), expected_title);
     NavigateToURL(window, url);
-    string16 final_title = title_watcher.WaitAndGetTitle();
+    base::string16 final_title = title_watcher.WaitAndGetTitle();
     EXPECT_EQ(expected_title, final_title);
   }
 
@@ -275,10 +275,10 @@ IN_PROC_BROWSER_TEST_F(WorkerTest, WebSocketSharedWorker) {
 
   // Run test.
   Shell* window = shell();
-  const string16 expected_title = ASCIIToUTF16("OK");
+  const base::string16 expected_title = ASCIIToUTF16("OK");
   TitleWatcher title_watcher(window->web_contents(), expected_title);
   NavigateToURL(window, url);
-  string16 final_title = title_watcher.WaitAndGetTitle();
+  base::string16 final_title = title_watcher.WaitAndGetTitle();
   EXPECT_EQ(expected_title, final_title);
 }
 
diff --git a/content/browser/worker_host/worker_process_host.cc b/content/browser/worker_host/worker_process_host.cc
index 08277da..fae589b 100644
--- a/content/browser/worker_host/worker_process_host.cc
+++ b/content/browser/worker_host/worker_process_host.cc
@@ -372,8 +372,8 @@ void WorkerProcessHost::OnWorkerContextClosed(int worker_route_id) {
 
 void WorkerProcessHost::OnAllowDatabase(int worker_route_id,
                                         const GURL& url,
-                                        const string16& name,
-                                        const string16& display_name,
+                                        const base::string16& name,
+                                        const base::string16& display_name,
                                         unsigned long estimated_size,
                                         bool* result) {
   *result = GetContentClient()->browser()->AllowWorkerDatabase(
@@ -390,7 +390,7 @@ void WorkerProcessHost::OnAllowFileSystem(int worker_route_id,
 
 void WorkerProcessHost::OnAllowIndexedDB(int worker_route_id,
                                          const GURL& url,
-                                         const string16& name,
+                                         const base::string16& name,
                                          bool* result) {
   *result = GetContentClient()->browser()->AllowWorkerIndexedDB(
       url, name, resource_context_, GetRenderViewIDsForWorker(worker_route_id));
@@ -572,7 +572,7 @@ net::URLRequestContext* WorkerProcessHost::GetRequestContext(
 
 WorkerProcessHost::WorkerInstance::WorkerInstance(
     const GURL& url,
-    const string16& name,
+    const base::string16& name,
     int worker_route_id,
     int parent_process_id,
     int64 main_resource_appcache_id,
@@ -593,7 +593,7 @@ WorkerProcessHost::WorkerInstance::WorkerInstance(
 WorkerProcessHost::WorkerInstance::WorkerInstance(
     const GURL& url,
     bool shared,
-    const string16& name,
+    const base::string16& name,
     ResourceContext* resource_context,
     const WorkerStoragePartition& partition)
     : url_(url),
@@ -618,7 +618,7 @@ WorkerProcessHost::WorkerInstance::~WorkerInstance() {
 // b) the names are both empty, and the urls are equal
 bool WorkerProcessHost::WorkerInstance::Matches(
     const GURL& match_url,
-    const string16& match_name,
+    const base::string16& match_name,
     const WorkerStoragePartition& partition,
     ResourceContext* resource_context) const {
   // Only match open shared workers.
diff --git a/content/browser/worker_host/worker_process_host.h b/content/browser/worker_host/worker_process_host.h
index 0a9ea60..c3fa64d 100644
--- a/content/browser/worker_host/worker_process_host.h
+++ b/content/browser/worker_host/worker_process_host.h
@@ -57,7 +57,7 @@ class WorkerProcessHost : public BrowserChildProcessHostDelegate,
   class WorkerInstance {
    public:
     WorkerInstance(const GURL& url,
-                   const string16& name,
+                   const base::string16& name,
                    int worker_route_id,
                    int parent_process_id,
                    int64 main_resource_appcache_id,
@@ -66,7 +66,7 @@ class WorkerProcessHost : public BrowserChildProcessHostDelegate,
     // Used for pending instances. Rest of the parameters are ignored.
     WorkerInstance(const GURL& url,
                    bool shared,
-                   const string16& name,
+                   const base::string16& name,
                    ResourceContext* resource_context,
                    const WorkerStoragePartition& partition);
     ~WorkerInstance();
@@ -92,7 +92,7 @@ class WorkerProcessHost : public BrowserChildProcessHostDelegate,
     // applies to shared workers.
     bool Matches(
         const GURL& url,
-        const string16& name,
+        const base::string16& name,
         const WorkerStoragePartition& partition,
         ResourceContext* resource_context) const;
 
@@ -107,7 +107,7 @@ class WorkerProcessHost : public BrowserChildProcessHostDelegate,
     bool closed() const { return closed_; }
     void set_closed(bool closed) { closed_ = closed; }
     const GURL& url() const { return url_; }
-    const string16 name() const { return name_; }
+    const base::string16 name() const { return name_; }
     int worker_route_id() const { return worker_route_id_; }
     int parent_process_id() const { return parent_process_id_; }
     int64 main_resource_appcache_id() const {
@@ -127,7 +127,7 @@ class WorkerProcessHost : public BrowserChildProcessHostDelegate,
     // Set of all filters (clients) associated with this worker.
     GURL url_;
     bool closed_;
-    string16 name_;
+    base::string16 name_;
     int worker_route_id_;
     int parent_process_id_;
     int64 main_resource_appcache_id_;
@@ -196,8 +196,8 @@ class WorkerProcessHost : public BrowserChildProcessHostDelegate,
   void OnWorkerContextClosed(int worker_route_id);
   void OnAllowDatabase(int worker_route_id,
                        const GURL& url,
-                       const string16& name,
-                       const string16& display_name,
+                       const base::string16& name,
+                       const base::string16& display_name,
                        unsigned long estimated_size,
                        bool* result);
   void OnAllowFileSystem(int worker_route_id,
@@ -205,7 +205,7 @@ class WorkerProcessHost : public BrowserChildProcessHostDelegate,
                          bool* result);
   void OnAllowIndexedDB(int worker_route_id,
                         const GURL& url,
-                        const string16& name,
+                        const base::string16& name,
                         bool* result);
   void OnForceKillWorkerProcess();
 
diff --git a/content/browser/worker_host/worker_service_impl.cc b/content/browser/worker_host/worker_service_impl.cc
index d2ab272..3ebab46 100644
--- a/content/browser/worker_host/worker_service_impl.cc
+++ b/content/browser/worker_host/worker_service_impl.cc
@@ -650,7 +650,7 @@ void WorkerServiceImpl::NotifyWorkerProcessCreated() {
 
 WorkerProcessHost::WorkerInstance* WorkerServiceImpl::FindSharedWorkerInstance(
     const GURL& url,
-    const string16& name,
+    const base::string16& name,
     const WorkerStoragePartition& partition,
     ResourceContext* resource_context) {
   for (WorkerProcessHostIterator iter; !iter.Done(); ++iter) {
@@ -667,7 +667,7 @@ WorkerProcessHost::WorkerInstance* WorkerServiceImpl::FindSharedWorkerInstance(
 
 WorkerProcessHost::WorkerInstance* WorkerServiceImpl::FindPendingInstance(
     const GURL& url,
-    const string16& name,
+    const base::string16& name,
     const WorkerStoragePartition& partition,
     ResourceContext* resource_context) {
   // Walk the pending instances looking for a matching pending worker.
@@ -684,7 +684,7 @@ WorkerProcessHost::WorkerInstance* WorkerServiceImpl::FindPendingInstance(
 
 void WorkerServiceImpl::RemovePendingInstances(
     const GURL& url,
-    const string16& name,
+    const base::string16& name,
     const WorkerStoragePartition& partition,
     ResourceContext* resource_context) {
   // Walk the pending instances looking for a matching pending worker.
@@ -701,7 +701,7 @@ void WorkerServiceImpl::RemovePendingInstances(
 
 WorkerProcessHost::WorkerInstance* WorkerServiceImpl::CreatePendingInstance(
     const GURL& url,
-    const string16& name,
+    const base::string16& name,
     ResourceContext* resource_context,
     const WorkerStoragePartition& partition) {
   // Look for an existing pending shared worker.
diff --git a/content/browser/worker_host/worker_service_impl.h b/content/browser/worker_host/worker_service_impl.h
index 9da0d19..4d5127a 100644
--- a/content/browser/worker_host/worker_service_impl.h
+++ b/content/browser/worker_host/worker_service_impl.h
@@ -108,23 +108,23 @@ class CONTENT_EXPORT WorkerServiceImpl
   // APIs for manipulating our set of pending shared worker instances.
   WorkerProcessHost::WorkerInstance* CreatePendingInstance(
       const GURL& url,
-      const string16& name,
+      const base::string16& name,
       ResourceContext* resource_context,
       const WorkerStoragePartition& worker_partition);
   WorkerProcessHost::WorkerInstance* FindPendingInstance(
       const GURL& url,
-      const string16& name,
+      const base::string16& name,
       const WorkerStoragePartition& worker_partition,
       ResourceContext* resource_context);
   void RemovePendingInstances(
       const GURL& url,
-      const string16& name,
+      const base::string16& name,
       const WorkerStoragePartition& worker_partition,
       ResourceContext* resource_context);
 
   WorkerProcessHost::WorkerInstance* FindSharedWorkerInstance(
       const GURL& url,
-      const string16& name,
+      const base::string16& name,
       const WorkerStoragePartition& worker_partition,
       ResourceContext* resource_context);
 
diff --git a/content/child/browser_font_resource_trusted.cc b/content/child/browser_font_resource_trusted.cc
index 35ad824..be4a8b6 100644
--- a/content/child/browser_font_resource_trusted.cc
+++ b/content/child/browser_font_resource_trusted.cc
@@ -43,14 +43,14 @@ namespace {
 // undefined reference linker error.
 const char kCommonScript[] = "Zyyy";
 
-string16 GetFontFromMap(
+base::string16 GetFontFromMap(
     const webkit_glue::ScriptFontFamilyMap& map,
     const std::string& script) {
   webkit_glue::ScriptFontFamilyMap::const_iterator it =
       map.find(script);
   if (it != map.end())
     return it->second;
-  return string16();
+  return base::string16();
 }
 
 // Splits a PP_BrowserFont_Trusted_TextRun into a sequence or LTR and RTL
@@ -85,7 +85,7 @@ class TextRunCollection {
       ubidi_close(bidi_);
   }
 
-  const string16& text() const { return text_; }
+  const base::string16& text() const { return text_; }
   int num_runs() const { return num_runs_; }
 
   // Returns a WebTextRun with the info for the run at the given index.
@@ -94,7 +94,7 @@ class TextRunCollection {
     DCHECK(index < num_runs_);
     if (bidi_) {
       bool run_rtl = !!ubidi_getVisualRun(bidi_, index, run_start, run_len);
-      return WebTextRun(string16(&text_[*run_start], *run_len),
+      return WebTextRun(base::string16(&text_[*run_start], *run_len),
                         run_rtl, true);
     }
 
@@ -110,7 +110,7 @@ class TextRunCollection {
   UBiDi* bidi_;
 
   // Text of all the runs.
-  string16 text_;
+  base::string16 text_;
 
   int num_runs_;
 
@@ -167,7 +167,7 @@ WebFontDescription PPFontDescToWebFontDesc(
   StringVar* face_name = StringVar::FromPPVar(font.face);  // Possibly null.
 
   WebFontDescription result;
-  string16 resolved_family;
+  base::string16 resolved_family;
   if (!face_name || face_name->value().empty()) {
     // Resolve the generic family.
     switch (font.family) {
diff --git a/content/child/db_message_filter.cc b/content/child/db_message_filter.cc
index 93fe885..f50d080 100644
--- a/content/child/db_message_filter.cc
+++ b/content/child/db_message_filter.cc
@@ -31,7 +31,7 @@ bool DBMessageFilter::OnMessageReceived(const IPC::Message& message) {
 }
 
 void DBMessageFilter::OnDatabaseUpdateSize(const std::string& origin_identifier,
-                                           const string16& database_name,
+                                           const base::string16& database_name,
                                            int64 database_size) {
   blink::WebDatabase::updateDatabaseSize(
       WebString::fromUTF8(origin_identifier), database_name, database_size);
@@ -52,7 +52,7 @@ void DBMessageFilter::OnDatabaseResetSpaceAvailable(
 
 void DBMessageFilter::OnDatabaseCloseImmediately(
     const std::string& origin_identifier,
-    const string16& database_name) {
+    const base::string16& database_name) {
   blink::WebDatabase::closeDatabaseImmediately(
       WebString::fromUTF8(origin_identifier), database_name);
 }
diff --git a/content/child/db_message_filter.h b/content/child/db_message_filter.h
index e918df6..4950006 100644
--- a/content/child/db_message_filter.h
+++ b/content/child/db_message_filter.h
@@ -23,13 +23,13 @@ class DBMessageFilter : public IPC::ChannelProxy::MessageFilter {
 
  private:
   void OnDatabaseUpdateSize(const std::string& origin_identifier,
-                            const string16& database_name,
+                            const base::string16& database_name,
                             int64 database_size);
   void OnDatabaseUpdateSpaceAvailable(const std::string& origin_identifier,
                                       int64 space_available);
   void OnDatabaseResetSpaceAvailable(const std::string& origin_identifier);
   void OnDatabaseCloseImmediately(const std::string& origin_identifier,
-                                  const string16& database_name);
+                                  const base::string16& database_name);
 };
 
 }  // namespace content
diff --git a/content/child/indexed_db/indexed_db_dispatcher.cc b/content/child/indexed_db/indexed_db_dispatcher.cc
index 2b97b4a..9fa1d66 100644
--- a/content/child/indexed_db/indexed_db_dispatcher.cc
+++ b/content/child/indexed_db/indexed_db_dispatcher.cc
@@ -213,7 +213,7 @@ void IndexedDBDispatcher::RequestIDBCursorPrefetchReset(int used_prefetches,
 }
 
 void IndexedDBDispatcher::RequestIDBFactoryOpen(
-    const string16& name,
+    const base::string16& name,
     int64 version,
     int64 transaction_id,
     WebIDBCallbacks* callbacks_ptr,
@@ -250,7 +250,7 @@ void IndexedDBDispatcher::RequestIDBFactoryGetDatabaseNames(
 }
 
 void IndexedDBDispatcher::RequestIDBFactoryDeleteDatabase(
-    const string16& name,
+    const base::string16& name,
     WebIDBCallbacks* callbacks_ptr,
     const std::string& database_identifier) {
   ResetCursorPrefetchCaches();
@@ -487,7 +487,7 @@ void IndexedDBDispatcher::OnSuccessIndexedDBKey(int32 ipc_thread_id,
 void IndexedDBDispatcher::OnSuccessStringList(
     int32 ipc_thread_id,
     int32 ipc_callbacks_id,
-    const std::vector<string16>& value) {
+    const std::vector<base::string16>& value) {
   DCHECK_EQ(ipc_thread_id, CurrentWorkerId());
   WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(ipc_callbacks_id);
   if (!callbacks)
@@ -652,7 +652,7 @@ void IndexedDBDispatcher::OnUpgradeNeeded(
 void IndexedDBDispatcher::OnError(int32 ipc_thread_id,
                                   int32 ipc_callbacks_id,
                                   int code,
-                                  const string16& message) {
+                                  const base::string16& message) {
   DCHECK_EQ(ipc_thread_id, CurrentWorkerId());
   WebIDBCallbacks* callbacks = pending_callbacks_.Lookup(ipc_callbacks_id);
   if (!callbacks)
@@ -668,7 +668,7 @@ void IndexedDBDispatcher::OnAbort(int32 ipc_thread_id,
                                   int32 ipc_database_callbacks_id,
                                   int64 transaction_id,
                                   int code,
-                                  const string16& message) {
+                                  const base::string16& message) {
   DCHECK_EQ(ipc_thread_id, CurrentWorkerId());
   WebIDBDatabaseCallbacks* callbacks =
       pending_database_callbacks_.Lookup(ipc_database_callbacks_id);
diff --git a/content/child/indexed_db/indexed_db_dispatcher.h b/content/child/indexed_db/indexed_db_dispatcher.h
index 6d60e29..a9f3653 100644
--- a/content/child/indexed_db/indexed_db_dispatcher.h
+++ b/content/child/indexed_db/indexed_db_dispatcher.h
@@ -71,14 +71,14 @@ class CONTENT_EXPORT IndexedDBDispatcher
       const std::string& database_identifier);
 
   void RequestIDBFactoryOpen(
-      const string16& name,
+      const base::string16& name,
       int64 version,
       int64 transaction_id,
       blink::WebIDBCallbacks* callbacks,
       blink::WebIDBDatabaseCallbacks* database_callbacks,
       const std::string& database_identifier);
 
-  void RequestIDBFactoryDeleteDatabase(const string16& name,
+  void RequestIDBFactoryDeleteDatabase(const base::string16& name,
                                        blink::WebIDBCallbacks* callbacks,
                                        const std::string& database_identifier);
 
@@ -192,7 +192,7 @@ class CONTENT_EXPORT IndexedDBDispatcher
       const IndexedDBMsg_CallbacksSuccessCursorPrefetch_Params& p);
   void OnSuccessStringList(int32 ipc_thread_id,
                            int32 ipc_callbacks_id,
-                           const std::vector<string16>& value);
+                           const std::vector<base::string16>& value);
   void OnSuccessValue(int32 ipc_thread_id,
                       int32 ipc_callbacks_id,
                       const std::string& value);
@@ -208,7 +208,7 @@ class CONTENT_EXPORT IndexedDBDispatcher
   void OnError(int32 ipc_thread_id,
                int32 ipc_callbacks_id,
                int code,
-               const string16& message);
+               const base::string16& message);
   void OnIntBlocked(int32 ipc_thread_id,
                     int32 ipc_callbacks_id,
                     int64 existing_version);
@@ -217,7 +217,7 @@ class CONTENT_EXPORT IndexedDBDispatcher
                int32 ipc_database_id,
                int64 transaction_id,
                int code,
-               const string16& message);
+               const base::string16& message);
   void OnComplete(int32 ipc_thread_id,
                   int32 ipc_database_id,
                   int64 transaction_id);
diff --git a/content/child/indexed_db/indexed_db_key_builders.cc b/content/child/indexed_db/indexed_db_key_builders.cc
index a17065f..ed84ac4 100644
--- a/content/child/indexed_db/indexed_db_key_builders.cc
+++ b/content/child/indexed_db/indexed_db_key_builders.cc
@@ -30,9 +30,9 @@ static content::IndexedDBKey::KeyArray CopyKeyArray(const WebIDBKey& other) {
   return result;
 }
 
-static std::vector<string16> CopyArray(
+static std::vector<base::string16> CopyArray(
     const WebVector<WebString>& array) {
-  std::vector<string16> copy(array.size());
+  std::vector<base::string16> copy(array.size());
   for (size_t i = 0; i < array.size(); ++i)
     copy[i] = array[i];
   return copy;
diff --git a/content/child/plugin_messages.h b/content/child/plugin_messages.h
index 404439f..92651e9 100644
--- a/content/child/plugin_messages.h
+++ b/content/child/plugin_messages.h
@@ -111,7 +111,7 @@ IPC_SYNC_MESSAGE_ROUTED0_1(PluginMsg_GetPluginScriptableObject,
 
 // Gets the form value of the plugin instance synchronously.
 IPC_SYNC_MESSAGE_ROUTED0_2(PluginMsg_GetFormValue,
-                           string16 /* value */,
+                           base::string16 /* value */,
                            bool /* success */)
 
 IPC_MESSAGE_ROUTED3(PluginMsg_DidFinishLoadWithReason,
@@ -197,13 +197,13 @@ IPC_MESSAGE_CONTROL1(PluginHostMsg_DidAbortLoading,
 
 #if defined(OS_WIN)
 IPC_MESSAGE_ROUTED4(PluginMsg_ImeCompositionUpdated,
-                    string16 /* text */,
+                    base::string16 /* text */,
                     std::vector<int> /* clauses */,
                     std::vector<int>, /* target */
                     int /* cursor_position */)
 
 IPC_MESSAGE_ROUTED1(PluginMsg_ImeCompositionCompleted,
-                    string16 /* text */)
+                    base::string16 /* text */)
 #endif
 
 #if defined(OS_MACOSX)
@@ -222,7 +222,7 @@ IPC_MESSAGE_ROUTED2(PluginMsg_WindowFrameChanged,
                     gfx::Rect /* view_frame */)
 
 IPC_MESSAGE_ROUTED1(PluginMsg_ImeCompositionCompleted,
-                    string16 /* text */)
+                    base::string16 /* text */)
 
 // This message, used only on 10.6 and later, transmits the "fake"
 // window handle allocated by the browser on behalf of the renderer
diff --git a/content/child/service_worker/service_worker_dispatcher.cc b/content/child/service_worker/service_worker_dispatcher.cc
index f5103fb..28c4928 100644
--- a/content/child/service_worker/service_worker_dispatcher.cc
+++ b/content/child/service_worker/service_worker_dispatcher.cc
@@ -133,7 +133,7 @@ void ServiceWorkerDispatcher::OnRegistrationError(
     int32 thread_id,
     int32 request_id,
     WebServiceWorkerError::ErrorType error_type,
-    const string16& message) {
+    const base::string16& message) {
   WebServiceWorkerProvider::WebServiceWorkerCallbacks* callbacks =
       pending_callbacks_.Lookup(request_id);
   DCHECK(callbacks);
diff --git a/content/child/service_worker/service_worker_dispatcher.h b/content/child/service_worker/service_worker_dispatcher.h
index 51a1e21..ef2796b 100644
--- a/content/child/service_worker/service_worker_dispatcher.h
+++ b/content/child/service_worker/service_worker_dispatcher.h
@@ -65,7 +65,7 @@ class ServiceWorkerDispatcher : public webkit_glue::WorkerTaskRunner::Observer {
   void OnRegistrationError(int32 thread_id,
                            int32 request_id,
                            blink::WebServiceWorkerError::ErrorType error_type,
-                           const string16& message);
+                           const base::string16& message);
 
   IDMap<blink::WebServiceWorkerProvider::WebServiceWorkerCallbacks,
         IDMapOwnPointer> pending_callbacks_;
diff --git a/content/child/webkitplatformsupport_impl.cc b/content/child/webkitplatformsupport_impl.cc
index e474aa9..5b8cc79 100644
--- a/content/child/webkitplatformsupport_impl.cc
+++ b/content/child/webkitplatformsupport_impl.cc
@@ -17,7 +17,7 @@ WebKitPlatformSupportImpl::WebKitPlatformSupportImpl() {
 WebKitPlatformSupportImpl::~WebKitPlatformSupportImpl() {
 }
 
-string16 WebKitPlatformSupportImpl::GetLocalizedString(int message_id) {
+base::string16 WebKitPlatformSupportImpl::GetLocalizedString(int message_id) {
   return GetContentClient()->GetLocalizedString(message_id);
 }
 
diff --git a/content/child/webkitplatformsupport_impl.h b/content/child/webkitplatformsupport_impl.h
index e32483b..b4d5fc7 100644
--- a/content/child/webkitplatformsupport_impl.h
+++ b/content/child/webkitplatformsupport_impl.h
@@ -22,7 +22,7 @@ class CONTENT_EXPORT WebKitPlatformSupportImpl
   WebKitPlatformSupportImpl();
   virtual ~WebKitPlatformSupportImpl();
 
-  virtual string16 GetLocalizedString(int message_id) OVERRIDE;
+  virtual base::string16 GetLocalizedString(int message_id) OVERRIDE;
   virtual base::StringPiece GetDataResource(
       int resource_id,
       ui::ScaleFactor scale_factor) OVERRIDE;
diff --git a/content/child/webmessageportchannel_impl.cc b/content/child/webmessageportchannel_impl.cc
index aeb8475..7b0658e 100644
--- a/content/child/webmessageportchannel_impl.cc
+++ b/content/child/webmessageportchannel_impl.cc
@@ -202,7 +202,7 @@ bool WebMessagePortChannelImpl::OnMessageReceived(const IPC::Message& message) {
 }
 
 void WebMessagePortChannelImpl::OnMessage(
-    const string16& message,
+    const base::string16& message,
     const std::vector<int>& sent_message_port_ids,
     const std::vector<int>& new_routing_ids) {
   base::AutoLock auto_lock(lock_);
@@ -230,7 +230,7 @@ void WebMessagePortChannelImpl::OnMessagesQueued() {
     base::AutoLock auto_lock(lock_);
     queued_messages.reserve(message_queue_.size());
     while (!message_queue_.empty()) {
-      string16 message = message_queue_.front().message;
+      base::string16 message = message_queue_.front().message;
       const std::vector<WebMessagePortChannelImpl*>& channel_array =
           message_queue_.front().ports;
       std::vector<int> port_ids(channel_array.size());
diff --git a/content/child/webmessageportchannel_impl.h b/content/child/webmessageportchannel_impl.h
index 8390972..efc1e04 100644
--- a/content/child/webmessageportchannel_impl.h
+++ b/content/child/webmessageportchannel_impl.h
@@ -58,7 +58,7 @@ class WebMessagePortChannelImpl
   // IPC::Listener implementation.
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
-  void OnMessage(const string16& message,
+  void OnMessage(const base::string16& message,
                  const std::vector<int>& sent_message_port_ids,
                  const std::vector<int>& new_routing_ids);
   void OnMessagesQueued();
@@ -67,7 +67,7 @@ class WebMessagePortChannelImpl
     Message();
     ~Message();
 
-    string16 message;
+    base::string16 message;
     std::vector<WebMessagePortChannelImpl*> ports;
   };
 
diff --git a/content/common/android/address_parser.cc b/content/common/android/address_parser.cc
index f4587c8..15874fd3 100644
--- a/content/common/android/address_parser.cc
+++ b/content/common/android/address_parser.cc
@@ -48,7 +48,7 @@ namespace address_parser {
 
 using namespace internal;
 
-bool FindAddress(const string16& text, string16* address) {
+bool FindAddress(const base::string16& text, base::string16* address) {
   size_t start, end;
   if (FindAddress(text.begin(), text.end(), &start, &end)) {
     address->assign(text.substr(start, end));
@@ -57,8 +57,8 @@ bool FindAddress(const string16& text, string16* address) {
   return false;
 }
 
-bool FindAddress(const string16::const_iterator& begin,
-                 const string16::const_iterator& end,
+bool FindAddress(const base::string16::const_iterator& begin,
+                 const base::string16::const_iterator& end,
                  size_t* start_pos,
                  size_t* end_pos) {
   HouseNumberParser house_number_parser;
@@ -100,7 +100,7 @@ bool FindAddress(const string16::const_iterator& begin,
 
           // Check the number of address lines.
           if (tokenizer.token_is_delim() && newline_delimiters.find(
-              *tokenizer.token_begin()) != string16::npos) {
+              *tokenizer.token_begin()) != base::string16::npos) {
             ++num_lines;
           }
         } while (tokenizer.token_is_delim());
diff --git a/content/common/android/address_parser.h b/content/common/android/address_parser.h
index 71a3aba..1a12a32 100644
--- a/content/common/android/address_parser.h
+++ b/content/common/android/address_parser.h
@@ -17,14 +17,14 @@ namespace address_parser {
 // Find the first address in some chunk of text.  If an address is found in
 // |text| true is returned and the address is copied into |address|.
 // Otherwise, false is returned.
-bool FindAddress(const string16& text, string16* address);
+bool FindAddress(const base::string16& text, base::string16* address);
 
 // Find the first address in some chunk of test.  |begin| is the starting
 // position to search from, |end| is the position to search to.  |start_pos|
 // and |end_pos| are set to the starting and ending position of the address,
 // if found.
-CONTENT_EXPORT bool FindAddress(const string16::const_iterator& begin,
-                                const string16::const_iterator& end,
+CONTENT_EXPORT bool FindAddress(const base::string16::const_iterator& begin,
+                                const base::string16::const_iterator& end,
                                 size_t* start_pos,
                                 size_t* end_pos);
 
diff --git a/content/common/android/address_parser_internal.cc b/content/common/android/address_parser_internal.cc
index 0970b17..fe14d3b 100644
--- a/content/common/android/address_parser_internal.cc
+++ b/content/common/android/address_parser_internal.cc
@@ -20,23 +20,23 @@ const size_t kZipPlus4Digits = 9;
 // Maximum number of digits of a house number, including possible hyphens.
 const size_t kMaxHouseDigits = 5;
 
-char16 SafePreviousChar(const string16::const_iterator& it,
-    const string16::const_iterator& begin) {
+char16 SafePreviousChar(const base::string16::const_iterator& it,
+    const base::string16::const_iterator& begin) {
   if (it == begin)
     return ' ';
   return *(it - 1);
 }
 
-char16 SafeNextChar(const string16::const_iterator& it,
-    const string16::const_iterator& end) {
+char16 SafeNextChar(const base::string16::const_iterator& it,
+    const base::string16::const_iterator& end) {
   if (it == end)
     return ' ';
   return *(it + 1);
 }
 
-bool WordLowerCaseEqualsASCII(string16::const_iterator word_begin,
-    string16::const_iterator word_end, const char* ascii_to_match) {
-  for (string16::const_iterator it = word_begin; it != word_end;
+bool WordLowerCaseEqualsASCII(base::string16::const_iterator word_begin,
+    base::string16::const_iterator word_end, const char* ascii_to_match) {
+  for (base::string16::const_iterator it = word_begin; it != word_end;
       ++it, ++ascii_to_match) {
     if (!*ascii_to_match || base::ToLowerASCII(*it) != *ascii_to_match)
       return false;
@@ -44,10 +44,10 @@ bool WordLowerCaseEqualsASCII(string16::const_iterator word_begin,
   return *ascii_to_match == 0 || *ascii_to_match == ' ';
 }
 
-bool LowerCaseEqualsASCIIWithPlural(string16::const_iterator word_begin,
-    string16::const_iterator word_end, const char* ascii_to_match,
+bool LowerCaseEqualsASCIIWithPlural(base::string16::const_iterator word_begin,
+    base::string16::const_iterator word_end, const char* ascii_to_match,
     bool allow_plural) {
-  for (string16::const_iterator it = word_begin; it != word_end;
+  for (base::string16::const_iterator it = word_begin; it != word_end;
       ++it, ++ascii_to_match) {
     if (!*ascii_to_match && allow_plural && *it == 's' && it + 1 == word_end)
       return true;
@@ -66,8 +66,8 @@ namespace address_parser {
 
 namespace internal {
 
-Word::Word(const string16::const_iterator& begin,
-           const string16::const_iterator& end)
+Word::Word(const base::string16::const_iterator& begin,
+           const base::string16::const_iterator& end)
     : begin(begin),
       end(end) {
   DCHECK(begin <= end);
@@ -115,8 +115,8 @@ bool HouseNumberParser::CheckFinished(Word* word) const {
 }
 
 bool HouseNumberParser::Parse(
-    const string16::const_iterator& begin,
-    const string16::const_iterator& end, Word* word) {
+    const base::string16::const_iterator& begin,
+    const base::string16::const_iterator& end, Word* word) {
   it_ = begin_ = begin;
   end_ = end;
   ResetState();
@@ -417,7 +417,7 @@ bool IsZipValid(const Word& word, size_t state_index) {
   if (length != kZipDigits && length != kZipPlus4Digits + 1)
     return false;
 
-  for (string16::const_iterator it = word.begin; it != word.end; ++it) {
+  for (base::string16::const_iterator it = word.begin; it != word.end; ++it) {
     size_t pos = it - word.begin;
     if (IsAsciiDigit(*it) || (*it == '-' && pos == kZipDigits))
       continue;
diff --git a/content/common/android/address_parser_internal.h b/content/common/android/address_parser_internal.h
index f236afc..74af6c3 100644
--- a/content/common/android/address_parser_internal.h
+++ b/content/common/android/address_parser_internal.h
@@ -19,12 +19,12 @@ namespace internal {
 
 // Exposed for tests.
 struct CONTENT_EXPORT Word {
-  string16::const_iterator begin;
-  string16::const_iterator end;
+  base::string16::const_iterator begin;
+  base::string16::const_iterator end;
 
   Word() {}
-  Word(const string16::const_iterator& begin,
-       const string16::const_iterator& end);
+  Word(const base::string16::const_iterator& begin,
+       const base::string16::const_iterator& end);
 };
 
 // Exposed for tests.
@@ -32,8 +32,8 @@ class CONTENT_EXPORT HouseNumberParser {
  public:
   HouseNumberParser() {}
 
-  bool Parse(const string16::const_iterator& begin,
-             const string16::const_iterator& end,
+  bool Parse(const base::string16::const_iterator& begin,
+             const base::string16::const_iterator& end,
              Word* word);
 
  private:
@@ -48,9 +48,9 @@ class CONTENT_EXPORT HouseNumberParser {
 
   // Iterators to the beginning, current position and ending of the string
   // being currently parsed.
-  string16::const_iterator begin_;
-  string16::const_iterator it_;
-  string16::const_iterator end_;
+  base::string16::const_iterator begin_;
+  base::string16::const_iterator it_;
+  base::string16::const_iterator end_;
 
   // Number of digits found in the current result candidate.
   size_t num_digits_;
@@ -63,7 +63,7 @@ class CONTENT_EXPORT HouseNumberParser {
 };
 
 typedef std::vector<Word> WordList;
-typedef base::StringTokenizerT<string16, string16::const_iterator>
+typedef base::StringTokenizerT<base::string16, base::string16::const_iterator>
     String16Tokenizer;
 
 // These are exposed for tests.
diff --git a/content/common/android/address_parser_unittest.cc b/content/common/android/address_parser_unittest.cc
index 30497b2..1a8d17e 100644
--- a/content/common/android/address_parser_unittest.cc
+++ b/content/common/android/address_parser_unittest.cc
@@ -25,13 +25,13 @@ class AddressParserTest : public testing::Test {
   }
 
   std::string GetHouseNumber(const std::string& content) const {
-    string16 content_16 = UTF8ToUTF16(content);
-    string16 result;
+    base::string16 content_16 = UTF8ToUTF16(content);
+    base::string16 result;
 
     HouseNumberParser parser;
     Word word;
     if (parser.Parse(content_16.begin(), content_16.end(), &word))
-      result = string16(word.begin, word.end);
+      result = base::string16(word.begin, word.end);
     return UTF16ToUTF8(result);
   }
 
@@ -62,7 +62,7 @@ class AddressParserTest : public testing::Test {
     size_t state_index;
     EXPECT_TRUE(GetState(state, &state_index));
 
-    string16 zip_16 = UTF8ToUTF16(zip);
+    base::string16 zip_16 = UTF8ToUTF16(zip);
     WordList words;
     TokenizeWords(zip_16, &words);
     EXPECT_TRUE(words.size() == 1);
@@ -70,7 +70,7 @@ class AddressParserTest : public testing::Test {
   }
 
   bool IsLocationName(const std::string& street) const {
-    string16 street_16 = UTF8ToUTF16(street);
+    base::string16 street_16 = UTF8ToUTF16(street);
     WordList words;
     TokenizeWords(street_16, &words);
     EXPECT_TRUE(words.size() == 1);
@@ -78,8 +78,8 @@ class AddressParserTest : public testing::Test {
   }
 
   std::string FindAddress(const std::string& content) const {
-    string16 content_16 = UTF8ToUTF16(content);
-    string16 result_16;
+    base::string16 content_16 = UTF8ToUTF16(content);
+    base::string16 result_16;
     size_t start, end;
     if (::FindAddress(content_16.begin(), content_16.end(), &start, &end))
       result_16 = content_16.substr(start, end - start);
diff --git a/content/common/clipboard_messages.h b/content/common/clipboard_messages.h
index 60ce680..d212638 100644
--- a/content/common/clipboard_messages.h
+++ b/content/common/clipboard_messages.h
@@ -56,17 +56,17 @@ IPC_MESSAGE_CONTROL1(ClipboardHostMsg_Clear,
                      ui::ClipboardType /* type */)
 IPC_SYNC_MESSAGE_CONTROL1_2(ClipboardHostMsg_ReadAvailableTypes,
                             ui::ClipboardType /* type */,
-                            std::vector<string16> /* types */,
+                            std::vector<base::string16> /* types */,
                             bool /* contains filenames */)
 IPC_SYNC_MESSAGE_CONTROL1_1(ClipboardHostMsg_ReadText,
                             ui::ClipboardType /* type */,
-                            string16 /* result */)
+                            base::string16 /* result */)
 IPC_SYNC_MESSAGE_CONTROL1_1(ClipboardHostMsg_ReadAsciiText,
                             ui::ClipboardType /* type */,
                             std::string /* result */)
 IPC_SYNC_MESSAGE_CONTROL1_4(ClipboardHostMsg_ReadHTML,
                             ui::ClipboardType /* type */,
-                            string16 /* markup */,
+                            base::string16 /* markup */,
                             GURL /* url */,
                             uint32 /* fragment start */,
                             uint32 /* fragment end */)
@@ -79,13 +79,13 @@ IPC_SYNC_MESSAGE_CONTROL1_2(ClipboardHostMsg_ReadImage,
                             uint32 /* image size */)
 IPC_SYNC_MESSAGE_CONTROL2_1(ClipboardHostMsg_ReadCustomData,
                             ui::ClipboardType /* type */,
-                            string16 /* type */,
-                            string16 /* result */)
+                            base::string16 /* type */,
+                            base::string16 /* result */)
 IPC_SYNC_MESSAGE_CONTROL1_1(ClipboardHostMsg_ReadData,
                             ui::Clipboard::FormatType /* format */,
                             std::string /* result */)
 
 #if defined(OS_MACOSX)
 IPC_MESSAGE_CONTROL1(ClipboardHostMsg_FindPboardWriteStringAsync,
-                     string16 /* text */)
+                     base::string16 /* text */)
 #endif
diff --git a/content/common/database_messages.h b/content/common/database_messages.h
index 2a20947..849b347 100644
--- a/content/common/database_messages.h
+++ b/content/common/database_messages.h
@@ -15,7 +15,7 @@
 // Notifies the child process of the new database size
 IPC_MESSAGE_CONTROL3(DatabaseMsg_UpdateSize,
                      std::string /* the origin */,
-                     string16 /* the database name */,
+                     base::string16 /* the database name */,
                      int64 /* the new database size */)
 
 // Notifies the child process of the new space available
@@ -30,30 +30,30 @@ IPC_MESSAGE_CONTROL1(DatabaseMsg_ResetSpaceAvailable,
 // Asks the child process to close a database immediately
 IPC_MESSAGE_CONTROL2(DatabaseMsg_CloseImmediately,
                      std::string /* the origin */,
-                     string16 /* the database name */)
+                     base::string16 /* the database name */)
 
 // Database messages sent from the renderer to the browser.
 
 // Asks the browser process to open a DB file with the given name.
 IPC_SYNC_MESSAGE_CONTROL2_1(DatabaseHostMsg_OpenFile,
-                            string16 /* vfs file name */,
+                            base::string16 /* vfs file name */,
                             int /* desired flags */,
                             IPC::PlatformFileForTransit /* file_handle */)
 
 // Asks the browser process to delete a DB file
 IPC_SYNC_MESSAGE_CONTROL2_1(DatabaseHostMsg_DeleteFile,
-                            string16 /* vfs file name */,
+                            base::string16 /* vfs file name */,
                             bool /* whether or not to sync the directory */,
                             int /* SQLite error code */)
 
 // Asks the browser process to return the attributes of a DB file
 IPC_SYNC_MESSAGE_CONTROL1_1(DatabaseHostMsg_GetFileAttributes,
-                            string16 /* vfs file name */,
+                            base::string16 /* vfs file name */,
                             int32 /* the attributes for the given DB file */)
 
 // Asks the browser process to return the size of a DB file
 IPC_SYNC_MESSAGE_CONTROL1_1(DatabaseHostMsg_GetFileSize,
-                            string16 /* vfs file name */,
+                            base::string16 /* vfs file name */,
                             int64 /* the size of the given DB file */)
 
 // Asks the browser process for the amount of space available to an origin
@@ -64,22 +64,22 @@ IPC_SYNC_MESSAGE_CONTROL1_1(DatabaseHostMsg_GetSpaceAvailable,
 // Notifies the browser process that a new database has been opened
 IPC_MESSAGE_CONTROL4(DatabaseHostMsg_Opened,
                      std::string /* origin identifier */,
-                     string16 /* database name */,
-                     string16 /* database description */,
+                     base::string16 /* database name */,
+                     base::string16 /* database description */,
                      int64 /* estimated size */)
 
 // Notifies the browser process that a database might have been modified
 IPC_MESSAGE_CONTROL2(DatabaseHostMsg_Modified,
                      std::string /* origin identifier */,
-                     string16 /* database name */)
+                     base::string16 /* database name */)
 
 // Notifies the browser process that a database is about to close
 IPC_MESSAGE_CONTROL2(DatabaseHostMsg_Closed,
                      std::string /* origin identifier */,
-                     string16 /* database name */)
+                     base::string16 /* database name */)
 
 // Sent when a sqlite error indicates the database is corrupt.
 IPC_MESSAGE_CONTROL3(DatabaseHostMsg_HandleSqliteError,
                      std::string /* origin identifier */,
-                     string16 /* database name */,
+                     base::string16 /* database name */,
                      int  /* error */)
diff --git a/content/common/desktop_notification_messages.h b/content/common/desktop_notification_messages.h
index 69c7d1f..6f1f0c4 100644
--- a/content/common/desktop_notification_messages.h
+++ b/content/common/desktop_notification_messages.h
@@ -31,7 +31,7 @@ IPC_MESSAGE_ROUTED1(DesktopNotificationMsg_PostDisplay,
 // trying to display a notification.
 IPC_MESSAGE_ROUTED2(DesktopNotificationMsg_PostError,
                     int /* notification_id */,
-                    string16 /* message */)
+                    base::string16 /* message */)
 
 // Informs the renderer that the one if its notifications has closed.
 IPC_MESSAGE_ROUTED2(DesktopNotificationMsg_PostClose,
diff --git a/content/common/dom_storage/dom_storage_messages.h b/content/common/dom_storage/dom_storage_messages.h
index 5aa96e3..2cf46e1 100644
--- a/content/common/dom_storage/dom_storage_messages.h
+++ b/content/common/dom_storage/dom_storage_messages.h
@@ -83,21 +83,21 @@ IPC_SYNC_MESSAGE_CONTROL1_2(DOMStorageHostMsg_LoadStorageArea,
 // A completion notification is sent in response.
 IPC_MESSAGE_CONTROL4(DOMStorageHostMsg_SetItem,
                      int /* connection_id */,
-                     string16 /* key */,
-                     string16 /* value */,
+                     base::string16 /* key */,
+                     base::string16 /* value */,
                      GURL /* page_url */)
 
 // Logs that a get operation was performed on a key/value pair.
 IPC_MESSAGE_CONTROL3(DOMStorageHostMsg_LogGetItem,
                      int /* connection_id */,
-                     string16 /* key */,
+                     base::string16 /* key */,
                      base::NullableString16 /* value */)
 
 // Remove the value associated with a key in a storage area.
 // A completion notification is sent in response.
 IPC_MESSAGE_CONTROL3(DOMStorageHostMsg_RemoveItem,
                      int /* connection_id */,
-                     string16 /* key */,
+                     base::string16 /* key */,
                      GURL /* page_url */)
 
 // Clear the storage area. A completion notification is sent in response.
diff --git a/content/common/font_cache_dispatcher_win.cc b/content/common/font_cache_dispatcher_win.cc
index d6d59de..47c9c12 100644
--- a/content/common/font_cache_dispatcher_win.cc
+++ b/content/common/font_cache_dispatcher_win.cc
@@ -13,7 +13,7 @@
 
 namespace content {
 namespace {
-typedef std::vector<string16> FontNameVector;
+typedef std::vector<base::string16> FontNameVector;
 typedef std::map<FontCacheDispatcher*, FontNameVector> DispatcherToFontNames;
 
 class FontCache {
@@ -23,7 +23,7 @@ class FontCache {
   }
 
   void PreCacheFont(const LOGFONT& font, FontCacheDispatcher* dispatcher) {
-    typedef std::map<string16, FontCache::CacheElement> FontNameToElement;
+    typedef std::map<base::string16, FontCache::CacheElement> FontNameToElement;
 
     base::AutoLock lock(mutex_);
 
@@ -41,7 +41,7 @@ class FontCache {
     BOOL ret = GetTextMetrics(hdc, &tm);
     DCHECK(ret);
 
-    string16 font_name = font.lfFaceName;
+    base::string16 font_name = font.lfFaceName;
     int ref_count_inc = 1;
     FontNameVector::iterator it =
         std::find(dispatcher_font_map_[dispatcher].begin(),
@@ -68,7 +68,7 @@ class FontCache {
   }
 
   void ReleaseCachedFonts(FontCacheDispatcher* dispatcher) {
-    typedef std::map<string16, FontCache::CacheElement> FontNameToElement;
+    typedef std::map<base::string16, FontCache::CacheElement> FontNameToElement;
 
     base::AutoLock lock(mutex_);
 
@@ -125,7 +125,7 @@ class FontCache {
   FontCache() {
   }
 
-  std::map<string16, CacheElement> cache_;
+  std::map<base::string16, CacheElement> cache_;
   DispatcherToFontNames dispatcher_font_map_;
   base::Lock mutex_;
 
diff --git a/content/common/font_list_mac.mm b/content/common/font_list_mac.mm
index 4ffb3de..64a54cd 100644
--- a/content/common/font_list_mac.mm
+++ b/content/common/font_list_mac.mm
@@ -21,9 +21,9 @@ scoped_ptr<base::ListValue> GetFontList_SlowBlocking() {
     NSString* localized_family_name =
         [fontManager localizedNameForFamily:family_name face:nil];
     base::ListValue* font_item = new base::ListValue();
-    string16 family = base::SysNSStringToUTF16(family_name);
+    base::string16 family = base::SysNSStringToUTF16(family_name);
     font_item->Append(new base::StringValue(family));
-    string16 loc_family = base::SysNSStringToUTF16(localized_family_name);
+    base::string16 loc_family = base::SysNSStringToUTF16(localized_family_name);
     font_item->Append(new base::StringValue(loc_family));
     font_list->Append(font_item);
   }
diff --git a/content/common/font_list_win.cc b/content/common/font_list_win.cc
index 0eb84ed..bc6c1dc 100644
--- a/content/common/font_list_win.cc
+++ b/content/common/font_list_win.cc
@@ -17,12 +17,12 @@ static int CALLBACK EnumFontFamExProc(ENUMLOGFONTEXW* logical_font,
                                       NEWTEXTMETRICEXW* physical_font,
                                       DWORD font_type,
                                       LPARAM lparam) {
-  std::set<string16>* font_names =
-      reinterpret_cast<std::set<string16>*>(lparam);
+  std::set<base::string16>* font_names =
+      reinterpret_cast<std::set<base::string16>*>(lparam);
   if (font_names) {
     const LOGFONTW& lf = logical_font->elfLogFont;
     if (lf.lfFaceName[0] && lf.lfFaceName[0] != '@') {
-      string16 face_name(lf.lfFaceName);
+      base::string16 face_name(lf.lfFaceName);
       font_names->insert(face_name);
     }
   }
@@ -30,7 +30,7 @@ static int CALLBACK EnumFontFamExProc(ENUMLOGFONTEXW* logical_font,
 }
 
 scoped_ptr<base::ListValue> GetFontList_SlowBlocking() {
-  std::set<string16> font_names;
+  std::set<base::string16> font_names;
 
   LOGFONTW logfont;
   memset(&logfont, 0, sizeof(logfont));
@@ -42,7 +42,7 @@ scoped_ptr<base::ListValue> GetFontList_SlowBlocking() {
   ::ReleaseDC(NULL, hdc);
 
   scoped_ptr<base::ListValue> font_list(new base::ListValue);
-  std::set<string16>::iterator iter;
+  std::set<base::string16>::iterator iter;
   for (iter = font_names.begin(); iter != font_names.end(); ++iter) {
     base::ListValue* font_item = new base::ListValue();
     font_item->Append(new base::StringValue(*iter));
diff --git a/content/common/handle_enumerator_win.cc b/content/common/handle_enumerator_win.cc
index 4482d5b..7cda767 100644
--- a/content/common/handle_enumerator_win.cc
+++ b/content/common/handle_enumerator_win.cc
@@ -19,7 +19,7 @@
 namespace content {
 namespace {
 
-typedef std::map<const string16, HandleType> HandleTypeMap;
+typedef std::map<const base::string16, HandleType> HandleTypeMap;
 
 HandleTypeMap& MakeHandleTypeMap() {
   HandleTypeMap& handle_types = *(new HandleTypeMap());
@@ -52,7 +52,7 @@ void HandleEnumerator::EnumerateHandles() {
   std::string process_type =
       CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
           switches::kProcessType);
-  string16 output = ASCIIToUTF16(process_type);
+  base::string16 output = ASCIIToUTF16(process_type);
   output.append(ASCIIToUTF16(" process - Handles at shutdown:\n"));
   for (sandbox::HandleTable::Iterator sys_handle
       = handles.HandlesForProcess(::GetCurrentProcessId());
@@ -78,15 +78,15 @@ void HandleEnumerator::EnumerateHandles() {
   DVLOG(0) << output;
 }
 
-HandleType StringToHandleType(const string16& type) {
+HandleType StringToHandleType(const base::string16& type) {
   static HandleTypeMap handle_types = MakeHandleTypeMap();
   HandleTypeMap::iterator result = handle_types.find(type);
   return result != handle_types.end() ? result->second : OtherHandle;
 }
 
-string16 GetAccessString(HandleType handle_type,
+base::string16 GetAccessString(HandleType handle_type,
                                            ACCESS_MASK access) {
-  string16 output;
+  base::string16 output;
   if (access & GENERIC_READ)
     output.append(ASCIIToUTF16("\tGENERIC_READ\n"));
   if (access & GENERIC_WRITE)
diff --git a/content/common/handle_enumerator_win.h b/content/common/handle_enumerator_win.h
index 5fd4981..3caba84 100644
--- a/content/common/handle_enumerator_win.h
+++ b/content/common/handle_enumerator_win.h
@@ -31,9 +31,10 @@ enum HandleType {
   OtherHandle
 };
 
-static HandleType StringToHandleType(const string16& type);
+static HandleType StringToHandleType(const base::string16& type);
 
-static string16 GetAccessString(HandleType handle_type, ACCESS_MASK access);
+static base::string16 GetAccessString(HandleType handle_type,
+                                      ACCESS_MASK access);
 
 class HandleEnumerator : public base::RefCountedThreadSafe<HandleEnumerator> {
  public:
diff --git a/content/common/indexed_db/indexed_db_key.cc b/content/common/indexed_db/indexed_db_key.cc
index 71ddd6a..02610bf 100644
--- a/content/common/indexed_db/indexed_db_key.cc
+++ b/content/common/indexed_db/indexed_db_key.cc
@@ -76,11 +76,11 @@ IndexedDBKey::IndexedDBKey(const std::string& key)
       size_estimate_(kOverheadSize +
                      (key.length() * sizeof(std::string::value_type))) {}
 
-IndexedDBKey::IndexedDBKey(const string16& key)
+IndexedDBKey::IndexedDBKey(const base::string16& key)
     : type_(WebIDBKeyTypeString),
       string_(key),
       size_estimate_(kOverheadSize +
-                     (key.length() * sizeof(string16::value_type))) {}
+                     (key.length() * sizeof(base::string16::value_type))) {}
 
 IndexedDBKey::~IndexedDBKey() {}
 
diff --git a/content/common/indexed_db/indexed_db_key.h b/content/common/indexed_db/indexed_db_key.h
index b10eb1f..391b6d6 100644
--- a/content/common/indexed_db/indexed_db_key.h
+++ b/content/common/indexed_db/indexed_db_key.h
@@ -27,7 +27,7 @@ class CONTENT_EXPORT IndexedDBKey {
   IndexedDBKey(blink::WebIDBKeyType);  // must be Null or Invalid
   explicit IndexedDBKey(const KeyArray& array);
   explicit IndexedDBKey(const std::string& binary);
-  explicit IndexedDBKey(const string16& str);
+  explicit IndexedDBKey(const base::string16& str);
   IndexedDBKey(double number,
                blink::WebIDBKeyType type);  // must be date or number
   ~IndexedDBKey();
@@ -41,7 +41,7 @@ class CONTENT_EXPORT IndexedDBKey {
   blink::WebIDBKeyType type() const { return type_; }
   const std::vector<IndexedDBKey>& array() const { return array_; }
   const std::string& binary() const { return binary_; }
-  const string16& string() const { return string_; }
+  const base::string16& string() const { return string_; }
   double date() const { return date_; }
   double number() const { return number_; }
 
@@ -51,7 +51,7 @@ class CONTENT_EXPORT IndexedDBKey {
   blink::WebIDBKeyType type_;
   std::vector<IndexedDBKey> array_;
   std::string binary_;
-  string16 string_;
+  base::string16 string_;
   double date_;
   double number_;
 
diff --git a/content/common/indexed_db/indexed_db_key_path.cc b/content/common/indexed_db/indexed_db_key_path.cc
index b01de73..3783d42 100644
--- a/content/common/indexed_db/indexed_db_key_path.cc
+++ b/content/common/indexed_db/indexed_db_key_path.cc
@@ -14,20 +14,20 @@ using blink::WebIDBKeyPathTypeString;
 
 IndexedDBKeyPath::IndexedDBKeyPath() : type_(WebIDBKeyPathTypeNull) {}
 
-IndexedDBKeyPath::IndexedDBKeyPath(const string16& string)
+IndexedDBKeyPath::IndexedDBKeyPath(const base::string16& string)
     : type_(WebIDBKeyPathTypeString), string_(string) {}
 
-IndexedDBKeyPath::IndexedDBKeyPath(const std::vector<string16>& array)
+IndexedDBKeyPath::IndexedDBKeyPath(const std::vector<base::string16>& array)
     : type_(WebIDBKeyPathTypeArray), array_(array) {}
 
 IndexedDBKeyPath::~IndexedDBKeyPath() {}
 
-const std::vector<string16>& IndexedDBKeyPath::array() const {
+const std::vector<base::string16>& IndexedDBKeyPath::array() const {
   DCHECK(type_ == blink::WebIDBKeyPathTypeArray);
   return array_;
 }
 
-const string16& IndexedDBKeyPath::string() const {
+const base::string16& IndexedDBKeyPath::string() const {
   DCHECK(type_ == blink::WebIDBKeyPathTypeString);
   return string_;
 }
diff --git a/content/common/indexed_db/indexed_db_key_path.h b/content/common/indexed_db/indexed_db_key_path.h
index a17c193..ec5e861 100644
--- a/content/common/indexed_db/indexed_db_key_path.h
+++ b/content/common/indexed_db/indexed_db_key_path.h
@@ -17,21 +17,21 @@ namespace content {
 class CONTENT_EXPORT IndexedDBKeyPath {
  public:
   IndexedDBKeyPath();  // Defaults to blink::WebIDBKeyPathTypeNull.
-  explicit IndexedDBKeyPath(const string16&);
-  explicit IndexedDBKeyPath(const std::vector<string16>&);
+  explicit IndexedDBKeyPath(const base::string16&);
+  explicit IndexedDBKeyPath(const std::vector<base::string16>&);
   ~IndexedDBKeyPath();
 
   bool IsNull() const { return type_ == blink::WebIDBKeyPathTypeNull; }
   bool operator==(const IndexedDBKeyPath& other) const;
 
   blink::WebIDBKeyPathType type() const { return type_; }
-  const std::vector<string16>& array() const;
-  const string16& string() const;
+  const std::vector<base::string16>& array() const;
+  const base::string16& string() const;
 
  private:
   blink::WebIDBKeyPathType type_;
-  string16 string_;
-  std::vector<string16> array_;
+  base::string16 string_;
+  std::vector<base::string16> array_;
 };
 
 }  // namespace content
diff --git a/content/common/indexed_db/indexed_db_key_unittest.cc b/content/common/indexed_db/indexed_db_key_unittest.cc
index 7116062..ca52cc4 100644
--- a/content/common/indexed_db/indexed_db_key_unittest.cc
+++ b/content/common/indexed_db/indexed_db_key_unittest.cc
@@ -32,7 +32,7 @@ TEST(IndexedDBKeyTest, KeySizeEstimates) {
   keys.push_back(IndexedDBKey(date, blink::WebIDBKeyTypeDate));
   estimates.push_back(static_cast<size_t>(24));  // Overhead + sizeof(double).
 
-  const string16 string(1024, static_cast<char16>('X'));
+  const base::string16 string(1024, static_cast<char16>('X'));
   keys.push_back(IndexedDBKey(string));
   // Overhead + string length * sizeof(char16).
   estimates.push_back(static_cast<size_t>(2064));
diff --git a/content/common/indexed_db/indexed_db_messages.h b/content/common/indexed_db/indexed_db_messages.h
index 3fb9533..047fd0c 100644
--- a/content/common/indexed_db/indexed_db_messages.h
+++ b/content/common/indexed_db/indexed_db_messages.h
@@ -45,7 +45,7 @@ IPC_STRUCT_BEGIN(IndexedDBHostMsg_FactoryOpen_Params)
   // The string id of the origin doing the initiating.
   IPC_STRUCT_MEMBER(std::string, database_identifier)
   // The name of the database.
-  IPC_STRUCT_MEMBER(string16, name)
+  IPC_STRUCT_MEMBER(base::string16, name)
   // The transaction id used if a database upgrade is needed.
   IPC_STRUCT_MEMBER(int64, transaction_id)
   // The requested version of the database.
@@ -60,7 +60,7 @@ IPC_STRUCT_BEGIN(IndexedDBHostMsg_FactoryDeleteDatabase_Params)
   // The string id of the origin doing the initiating.
   IPC_STRUCT_MEMBER(std::string, database_identifier)
   // The name of the database.
-  IPC_STRUCT_MEMBER(string16, name)
+  IPC_STRUCT_MEMBER(base::string16, name)
 IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(IndexedDBHostMsg_DatabaseCreateTransaction_Params)
@@ -86,7 +86,7 @@ IPC_STRUCT_BEGIN(IndexedDBHostMsg_DatabaseCreateObjectStore_Params)
   // The storage id of the object store.
   IPC_STRUCT_MEMBER(int64, object_store_id)
   // The name of the object store.
-  IPC_STRUCT_MEMBER(string16, name)
+  IPC_STRUCT_MEMBER(base::string16, name)
   // The keyPath of the object store.
   IPC_STRUCT_MEMBER(content::IndexedDBKeyPath, key_path)
   // Whether the object store created should have a key generator.
@@ -219,7 +219,7 @@ IPC_STRUCT_BEGIN(IndexedDBHostMsg_DatabaseCreateIndex_Params)
   // The storage id of the index.
   IPC_STRUCT_MEMBER(int64, index_id)
   // The name of the index.
-  IPC_STRUCT_MEMBER(string16, name)
+  IPC_STRUCT_MEMBER(base::string16, name)
   // The keyPath of the index.
   IPC_STRUCT_MEMBER(content::IndexedDBKeyPath, key_path)
   // Whether the index created has unique keys.
@@ -257,7 +257,7 @@ IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(IndexedDBIndexMetadata)
   IPC_STRUCT_MEMBER(int64, id)
-  IPC_STRUCT_MEMBER(string16, name)
+  IPC_STRUCT_MEMBER(base::string16, name)
   IPC_STRUCT_MEMBER(content::IndexedDBKeyPath, keyPath)
   IPC_STRUCT_MEMBER(bool, unique)
   IPC_STRUCT_MEMBER(bool, multiEntry)
@@ -265,7 +265,7 @@ IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(IndexedDBObjectStoreMetadata)
   IPC_STRUCT_MEMBER(int64, id)
-  IPC_STRUCT_MEMBER(string16, name)
+  IPC_STRUCT_MEMBER(base::string16, name)
   IPC_STRUCT_MEMBER(content::IndexedDBKeyPath, keyPath)
   IPC_STRUCT_MEMBER(bool, autoIncrement)
   IPC_STRUCT_MEMBER(int64, max_index_id)
@@ -274,8 +274,8 @@ IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(IndexedDBDatabaseMetadata)
   IPC_STRUCT_MEMBER(int64, id)
-  IPC_STRUCT_MEMBER(string16, name)
-  IPC_STRUCT_MEMBER(string16, version)
+  IPC_STRUCT_MEMBER(base::string16, name)
+  IPC_STRUCT_MEMBER(base::string16, version)
   IPC_STRUCT_MEMBER(int64, int_version)
   IPC_STRUCT_MEMBER(int64, max_object_store_id)
   IPC_STRUCT_MEMBER(std::vector<IndexedDBObjectStoreMetadata>, object_stores)
@@ -341,12 +341,12 @@ IPC_MESSAGE_CONTROL2(IndexedDBMsg_CallbacksSuccessUndefined,
 IPC_MESSAGE_CONTROL3(IndexedDBMsg_CallbacksSuccessStringList,
                      int32 /* ipc_thread_id */,
                      int32 /* ipc_callbacks_id */,
-                     std::vector<string16> /* dom_string_list */)
+                     std::vector<base::string16> /* dom_string_list */)
 IPC_MESSAGE_CONTROL4(IndexedDBMsg_CallbacksError,
                      int32 /* ipc_thread_id */,
                      int32 /* ipc_callbacks_id */,
                      int /* code */,
-                     string16 /* message */)
+                     base::string16 /* message */)
 IPC_MESSAGE_CONTROL2(IndexedDBMsg_CallbacksBlocked,
                      int32 /* ipc_thread_id */,
                      int32 /* ipc_callbacks_id */)
@@ -371,7 +371,7 @@ IPC_MESSAGE_CONTROL5(IndexedDBMsg_DatabaseCallbacksAbort,
                      int32, /* ipc_database_callbacks_id */
                      int64, /* transaction_id */
                      int, /* code */
-                     string16) /* message */
+                     base::string16) /* message */
 IPC_MESSAGE_CONTROL3(IndexedDBMsg_DatabaseCallbacksComplete,
                      int32, /* ipc_thread_id */
                      int32, /* ipc_database_callbacks_id */
diff --git a/content/common/indexed_db/indexed_db_param_traits.cc b/content/common/indexed_db/indexed_db_param_traits.cc
index 94b2053..0a566e2 100644
--- a/content/common/indexed_db/indexed_db_param_traits.cc
+++ b/content/common/indexed_db/indexed_db_param_traits.cc
@@ -82,7 +82,7 @@ bool ParamTraits<IndexedDBKey>::Read(const Message* m,
       return true;
     }
     case WebIDBKeyTypeString: {
-      string16 string;
+      base::string16 string;
       if (!ReadParam(m, iter, &string))
         return false;
       *r = IndexedDBKey(string);
@@ -156,14 +156,14 @@ bool ParamTraits<IndexedDBKeyPath>::Read(const Message* m,
 
   switch (type) {
     case WebIDBKeyPathTypeArray: {
-      std::vector<string16> array;
+      std::vector<base::string16> array;
       if (!ReadParam(m, iter, &array))
         return false;
       *r = IndexedDBKeyPath(array);
       return true;
     }
     case WebIDBKeyPathTypeString: {
-      string16 string;
+      base::string16 string;
       if (!ReadParam(m, iter, &string))
         return false;
       *r = IndexedDBKeyPath(string);
@@ -184,7 +184,7 @@ void ParamTraits<IndexedDBKeyPath>::Log(const param_type& p, std::string* l) {
   LogParam(p.string(), l);
   l->append(", ");
   l->append("[");
-  std::vector<string16>::const_iterator it = p.array().begin();
+  std::vector<base::string16>::const_iterator it = p.array().begin();
   while (it != p.array().end()) {
     LogParam(*it, l);
     ++it;
diff --git a/content/common/input_messages.h b/content/common/input_messages.h
index 57e51ce..230e851 100644
--- a/content/common/input_messages.h
+++ b/content/common/input_messages.h
@@ -131,10 +131,10 @@ IPC_MESSAGE_ROUTED0(InputMsg_PasteAndMatchStyle)
 // Replaces the selected region or a word around the cursor with the
 // specified string.
 IPC_MESSAGE_ROUTED1(InputMsg_Replace,
-                    string16)
+                    base::string16)
 // Replaces the misspelling in the selected region with the specified string.
 IPC_MESSAGE_ROUTED1(InputMsg_ReplaceMisspelling,
-                    string16)
+                    base::string16)
 IPC_MESSAGE_ROUTED0(InputMsg_Delete)
 IPC_MESSAGE_ROUTED0(InputMsg_SelectAll)
 
diff --git a/content/common/java_bridge_messages.h b/content/common/java_bridge_messages.h
index 7f2d8c1..6bb8116 100644
--- a/content/common/java_bridge_messages.h
+++ b/content/common/java_bridge_messages.h
@@ -18,12 +18,12 @@
 
 // Sent from browser to renderer to add a Java object with the given name.
 IPC_MESSAGE_ROUTED2(JavaBridgeMsg_AddNamedObject,
-                    string16 /* name */,
+                    base::string16 /* name */,
                     content::NPVariant_Param) /* object */
 
 // Sent from browser to renderer to remove a Java object with the given name.
 IPC_MESSAGE_ROUTED1(JavaBridgeMsg_RemoveNamedObject,
-                    string16 /* name */)
+                    base::string16 /* name */)
 
 // Sent from renderer to browser to request a route ID for a renderer-side (ie
 // JavaScript) object.
diff --git a/content/common/mac/attributed_string_coder.h b/content/common/mac/attributed_string_coder.h
index 629beed..35b3bf5 100644
--- a/content/common/mac/attributed_string_coder.h
+++ b/content/common/mac/attributed_string_coder.h
@@ -62,12 +62,12 @@ class CONTENT_EXPORT AttributedStringCoder {
   // which can be serialized over IPC.
   class EncodedString {
    public:
-    explicit EncodedString(string16 string);
+    explicit EncodedString(base::string16 string);
     EncodedString();
     ~EncodedString();
 
     // Accessors:
-    string16 string() const { return string_; }
+    base::string16 string() const { return string_; }
     const std::vector<FontAttribute>& attributes() const {
       return attributes_;
     }
@@ -75,7 +75,7 @@ class CONTENT_EXPORT AttributedStringCoder {
 
    private:
     // The plain-text string.
-    string16 string_;
+    base::string16 string_;
     // The set of attributes that style |string_|.
     std::vector<FontAttribute> attributes_;
   };
diff --git a/content/common/mac/attributed_string_coder.mm b/content/common/mac/attributed_string_coder.mm
index ba6eca5..f14103b 100644
--- a/content/common/mac/attributed_string_coder.mm
+++ b/content/common/mac/attributed_string_coder.mm
@@ -65,7 +65,7 @@ NSAttributedString* AttributedStringCoder::Decode(
 
 // Data Types //////////////////////////////////////////////////////////////////
 
-AttributedStringCoder::EncodedString::EncodedString(string16 string)
+AttributedStringCoder::EncodedString::EncodedString(base::string16 string)
     : string_(string) {
 }
 
@@ -129,7 +129,7 @@ bool ParamTraits<AttributedStringCoder::EncodedString>::Read(
     const Message* m, PickleIterator* iter, param_type* p) {
   bool success = true;
 
-  string16 result;
+  base::string16 result;
   success &= ReadParam(m, iter, &result);
   *p = AttributedStringCoder::EncodedString(result);
 
diff --git a/content/common/mac/font_descriptor.h b/content/common/mac/font_descriptor.h
index f47eb22..219f1fb 100644
--- a/content/common/mac/font_descriptor.h
+++ b/content/common/mac/font_descriptor.h
@@ -17,7 +17,7 @@ class NSFont;
 // Container to allow serializing an NSFont over IPC.
 struct CONTENT_EXPORT FontDescriptor {
   explicit FontDescriptor(NSFont* font);
-  FontDescriptor(string16 name, float size);
+  FontDescriptor(base::string16 name, float size);
 
   FontDescriptor() : font_point_size(0) {}
 
@@ -25,7 +25,7 @@ struct CONTENT_EXPORT FontDescriptor {
   NSFont* ToNSFont() const;
 
   // Name of the font.
-  string16 font_name;
+  base::string16 font_name;
 
   // Size in points.
   float font_point_size;
diff --git a/content/common/mac/font_descriptor.mm b/content/common/mac/font_descriptor.mm
index 3b5a577..e5c04c1 100644
--- a/content/common/mac/font_descriptor.mm
+++ b/content/common/mac/font_descriptor.mm
@@ -13,7 +13,7 @@ FontDescriptor::FontDescriptor(NSFont* font) {
   font_point_size = [font pointSize];
 }
 
-FontDescriptor::FontDescriptor(string16 name, float size) {
+FontDescriptor::FontDescriptor(base::string16 name, float size) {
   font_name = name;
   font_point_size = size;
 }
diff --git a/content/common/message_port_messages.h b/content/common/message_port_messages.h
index 67b729d..4269ade 100644
--- a/content/common/message_port_messages.h
+++ b/content/common/message_port_messages.h
@@ -25,7 +25,7 @@
 #ifndef CONTENT_COMMON_MESSAGE_PORT_MESSAGES_H_
 #define CONTENT_COMMON_MESSAGE_PORT_MESSAGES_H_
 
-typedef std::pair<string16, std::vector<int> > QueuedMessage;
+typedef std::pair<base::string16, std::vector<int> > QueuedMessage;
 
 #endif  // CONTENT_COMMON_MESSAGE_PORT_MESSAGES_H_
 
@@ -35,7 +35,7 @@ typedef std::pair<string16, std::vector<int> > QueuedMessage;
 
 // Sends a message to a message port.
 IPC_MESSAGE_ROUTED3(MessagePortMsg_Message,
-                    string16 /* message */,
+                    base::string16 /* message */,
                     std::vector<int> /* sent_message_port_ids */,
                     std::vector<int> /* new_routing_ids */)
 
@@ -62,7 +62,7 @@ IPC_MESSAGE_CONTROL1(MessagePortHostMsg_DestroyMessagePort,
 // as well if sent_message_port_id != MSG_ROUTING_NONE.
 IPC_MESSAGE_CONTROL3(MessagePortHostMsg_PostMessage,
                      int /* sender_message_port_id */,
-                     string16 /* message */,
+                     base::string16 /* message */,
                      std::vector<int> /* sent_message_port_ids */)
 
 // Causes messages sent to the remote port to be delivered to this local port.
diff --git a/content/common/sandbox_win.cc b/content/common/sandbox_win.cc
index f5c86f7..cf13a1d 100644
--- a/content/common/sandbox_win.cc
+++ b/content/common/sandbox_win.cc
@@ -217,7 +217,7 @@ void AddGenericDllEvictionPolicy(sandbox::TargetPolicy* policy) {
 }
 
 // Returns the object path prepended with the current logon session.
-string16 PrependWindowsSessionPath(const char16* object) {
+base::string16 PrependWindowsSessionPath(const char16* object) {
   // Cache this because it can't change after process creation.
   static uintptr_t s_session_id = 0;
   if (s_session_id == 0) {
@@ -514,7 +514,7 @@ void SetJobLevel(const CommandLine& cmd_line,
 // Just have to figure out what needs to be warmed up first.
 void AddBaseHandleClosePolicy(sandbox::TargetPolicy* policy) {
   // TODO(cpu): Add back the BaseNamedObjects policy.
-  string16 object_path = PrependWindowsSessionPath(
+  base::string16 object_path = PrependWindowsSessionPath(
       L"\\BaseNamedObjects\\windows_shell_global_counters");
   policy->AddKernelObjectToClose(L"Section", object_path.data());
 }
diff --git a/content/common/service_worker_messages.h b/content/common/service_worker_messages.h
index f5fe5dc..d2a5eb2 100644
--- a/content/common/service_worker_messages.h
+++ b/content/common/service_worker_messages.h
@@ -49,7 +49,7 @@ IPC_MESSAGE_CONTROL4(ServiceWorkerMsg_ServiceWorkerRegistrationError,
                      int32 /* thread_id */,
                      int32 /* request_id */,
                      blink::WebServiceWorkerError::ErrorType /* code */,
-                     string16 /* message */)
+                     base::string16 /* message */)
 
 // Informs the browser of a new ServiceWorkerProvider in the child process,
 // |provider_id| is unique within its child process.
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index 2e8d41a..3ff33ca 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -338,7 +338,7 @@ IPC_STRUCT_BEGIN(ViewHostMsg_CreateWindow_Params)
 
   // The name of the resulting frame that should be created (empty if none
   // has been specified).
-  IPC_STRUCT_MEMBER(string16, frame_name)
+  IPC_STRUCT_MEMBER(base::string16, frame_name)
 
   // The frame identifier of the frame initiating the open.
   IPC_STRUCT_MEMBER(int64, opener_frame_id)
@@ -373,7 +373,7 @@ IPC_STRUCT_BEGIN(ViewHostMsg_CreateWindow_Params)
   // The additional window features to use for the new view. We pass these
   // separately from |features| above because we cannot serialize WebStrings
   // over IPC.
-  IPC_STRUCT_MEMBER(std::vector<string16>, additional_features)
+  IPC_STRUCT_MEMBER(std::vector<base::string16>, additional_features)
 IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(ViewHostMsg_CreateWorker_Params)
@@ -381,7 +381,7 @@ IPC_STRUCT_BEGIN(ViewHostMsg_CreateWorker_Params)
   IPC_STRUCT_MEMBER(GURL, url)
 
   // Name for a SharedWorker, otherwise empty string.
-  IPC_STRUCT_MEMBER(string16, name)
+  IPC_STRUCT_MEMBER(base::string16, name)
 
   // The ID of the parent document (unique within parent renderer).
   IPC_STRUCT_MEMBER(unsigned long long, document_id)
@@ -417,14 +417,14 @@ IPC_STRUCT_BEGIN(ViewHostMsg_DidFailProvisionalLoadWithError_Params)
   // The frame ID for the failure report.
   IPC_STRUCT_MEMBER(int64, frame_id)
   // The WebFrame's uniqueName().
-  IPC_STRUCT_MEMBER(string16, frame_unique_name)
+  IPC_STRUCT_MEMBER(base::string16, frame_unique_name)
   // True if this is the top-most frame.
   IPC_STRUCT_MEMBER(bool, is_main_frame)
   // Error code as reported in the DidFailProvisionalLoad callback.
   IPC_STRUCT_MEMBER(int, error_code)
   // An error message generated from the error_code. This can be an empty
   // string if we were unable to find a meaningful description.
-  IPC_STRUCT_MEMBER(string16, error_description)
+  IPC_STRUCT_MEMBER(base::string16, error_description)
   // The URL that the error is reported for.
   IPC_STRUCT_MEMBER(GURL, url)
   // True if the failure is the result of navigating to a POST again
@@ -442,7 +442,7 @@ IPC_STRUCT_BEGIN_WITH_PARENT(ViewHostMsg_FrameNavigate_Params,
   IPC_STRUCT_MEMBER(int64, frame_id)
 
   // The WebFrame's uniqueName().
-  IPC_STRUCT_MEMBER(string16, frame_unique_name)
+  IPC_STRUCT_MEMBER(base::string16, frame_unique_name)
 
   // Information regarding the security of the connection (empty if the
   // connection was not secure).
@@ -735,7 +735,7 @@ IPC_STRUCT_BEGIN(ViewMsg_New_Params)
   IPC_STRUCT_MEMBER(int64, session_storage_namespace_id)
 
   // The name of the frame associated with this view (or empty if none).
-  IPC_STRUCT_MEMBER(string16, frame_name)
+  IPC_STRUCT_MEMBER(base::string16, frame_name)
 
   // The route ID of the opener RenderView if we need to set one
   // (MSG_ROUTING_NONE otherwise).
@@ -766,7 +766,7 @@ IPC_STRUCT_END()
 
 IPC_STRUCT_BEGIN(ViewMsg_PostMessage_Params)
   // The serialized script value.
-  IPC_STRUCT_MEMBER(string16, data)
+  IPC_STRUCT_MEMBER(base::string16, data)
 
   // When sent to the browser, this is the routing ID of the source frame in
   // the source process.  The browser replaces it with the routing ID of the
@@ -774,10 +774,10 @@ IPC_STRUCT_BEGIN(ViewMsg_PostMessage_Params)
   IPC_STRUCT_MEMBER(int, source_routing_id)
 
   // The origin of the source frame.
-  IPC_STRUCT_MEMBER(string16, source_origin)
+  IPC_STRUCT_MEMBER(base::string16, source_origin)
 
   // The origin for the message's target.
-  IPC_STRUCT_MEMBER(string16, target_origin)
+  IPC_STRUCT_MEMBER(base::string16, target_origin)
 
   // Information about the MessagePorts this message contains.
   IPC_STRUCT_MEMBER(std::vector<int>, message_port_ids)
@@ -961,7 +961,7 @@ IPC_MESSAGE_ROUTED0(ViewMsg_ReloadFrame)
 // Sent when the user wants to search for a word on the page (find in page).
 IPC_MESSAGE_ROUTED3(ViewMsg_Find,
                     int /* request_id */,
-                    string16 /* search_text */,
+                    base::string16 /* search_text */,
                     blink::WebFindOptions)
 
 // This message notifies the renderer that the user has closed the FindInPage
@@ -1020,8 +1020,8 @@ IPC_MESSAGE_ROUTED2(ViewMsg_PluginActionAt,
 // ViewHostMsg_ScriptEvalResponse is passed the ID parameter so that the
 // client can uniquely identify the request.
 IPC_MESSAGE_ROUTED4(ViewMsg_ScriptEvalRequest,
-                    string16,  /* frame_xpath */
-                    string16,  /* jscript_url */
+                    base::string16,  /* frame_xpath */
+                    base::string16,  /* jscript_url */
                     int,  /* ID */
                     bool  /* If true, result is sent back. */)
 
@@ -1036,7 +1036,7 @@ IPC_MESSAGE_ROUTED0(ViewMsg_DisownOpener)
 // into that frame's document. See ViewMsg_ScriptEvalRequest for details on
 // allowed xpath expressions.
 IPC_MESSAGE_ROUTED2(ViewMsg_CSSInsertRequest,
-                    string16,  /* frame_xpath */
+                    base::string16,  /* frame_xpath */
                     std::string  /* css string */)
 
 // Change the zoom level for the current main frame.  If the level actually
@@ -1113,14 +1113,14 @@ IPC_MESSAGE_ROUTED0(ViewMsg_CandidateWindowHidden)
 // This message sends a string being composed with an input method.
 IPC_MESSAGE_ROUTED4(
     ViewMsg_ImeSetComposition,
-    string16, /* text */
+    base::string16, /* text */
     std::vector<blink::WebCompositionUnderline>, /* underlines */
     int, /* selectiont_start */
     int /* selection_end */)
 
 // This message confirms an ongoing composition.
 IPC_MESSAGE_ROUTED3(ViewMsg_ImeConfirmComposition,
-                    string16 /* text */,
+                    base::string16 /* text */,
                     gfx::Range /* replacement_range */,
                     bool /* keep_selection */)
 
@@ -1376,7 +1376,7 @@ IPC_MESSAGE_ROUTED1(ViewMsg_SetInLiveResize,
 
 // Tell the renderer that plugin IME has completed.
 IPC_MESSAGE_ROUTED2(ViewMsg_PluginImeCompositionCompleted,
-                    string16 /* text */,
+                    base::string16 /* text */,
                     int /* plugin_id */)
 
 // External popup menus.
@@ -1584,7 +1584,7 @@ IPC_MESSAGE_ROUTED3(ViewHostMsg_DidFinishLoad,
 // title changes.
 IPC_MESSAGE_ROUTED3(ViewHostMsg_UpdateTitle,
                     int32 /* page_id */,
-                    string16 /* title */,
+                    base::string16 /* title */,
                     blink::WebTextDirection /* title direction */)
 
 // Change the encoding name of the page in UI when the page has detected
@@ -1649,7 +1649,7 @@ IPC_MESSAGE_ROUTED5(ViewHostMsg_DidFailLoadWithError,
                     GURL /* validated_url */,
                     bool /* is_main_frame */,
                     int /* error_code */,
-                    string16 /* error_description */)
+                    base::string16 /* error_description */)
 
 // Sent when the renderer fails a provisional load with an error.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_DidFailProvisionalLoadWithError,
@@ -1811,7 +1811,7 @@ IPC_MESSAGE_ROUTED2(ViewHostMsg_AppCacheAccessed,
 IPC_MESSAGE_ROUTED3(ViewHostMsg_DownloadUrl,
                     GURL     /* url */,
                     content::Referrer /* referrer */,
-                    string16 /* suggested_name */)
+                    base::string16 /* suggested_name */)
 
 // Used to go to the session history entry at the given offset (ie, -1 will
 // return the "back" item).
@@ -1828,12 +1828,12 @@ IPC_MESSAGE_ROUTED1(ViewHostMsg_RouteMessageEvent,
                     ViewMsg_PostMessage_Params)
 
 IPC_SYNC_MESSAGE_ROUTED4_2(ViewHostMsg_RunJavaScriptMessage,
-                           string16     /* in - alert message */,
-                           string16     /* in - default prompt */,
+                           base::string16     /* in - alert message */,
+                           base::string16     /* in - default prompt */,
                            GURL         /* in - originating page URL */,
                            content::JavaScriptMessageType /* in - type */,
                            bool         /* out - success */,
-                           string16     /* out - user_input field */)
+                           base::string16     /* out - user_input field */)
 
 // Requests that the given URL be opened in the specified manner.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_OpenURL, ViewHostMsg_OpenURL_Params)
@@ -1962,7 +1962,7 @@ IPC_SYNC_MESSAGE_ROUTED1_0(ViewHostMsg_DestroyPluginContainer,
 
 // Send the tooltip text for the current mouse position to the browser.
 IPC_MESSAGE_ROUTED2(ViewHostMsg_SetTooltipText,
-                    string16 /* tooltip text string */,
+                    base::string16 /* tooltip text string */,
                     blink::WebTextDirection /* text direction hint */)
 
 IPC_MESSAGE_ROUTED0(ViewHostMsg_SelectRange_ACK)
@@ -1972,7 +1972,7 @@ IPC_MESSAGE_ROUTED0(ViewHostMsg_MoveCaret_ACK)
 // Note: The secound parameter is the character based offset of the string16
 // text in the document.
 IPC_MESSAGE_ROUTED3(ViewHostMsg_SelectionChanged,
-                    string16 /* text covers the selection range */,
+                    base::string16 /* text covers the selection range */,
                     size_t /* the offset of the text in the document */,
                     gfx::Range /* selection range in the document */)
 
@@ -2032,9 +2032,9 @@ IPC_MESSAGE_ROUTED0(ViewHostMsg_ImeCancelComposition)
 // or debugger UI.
 IPC_MESSAGE_ROUTED4(ViewHostMsg_AddMessageToConsole,
                     int32, /* log level */
-                    string16, /* msg */
+                    base::string16, /* msg */
                     int32, /* line number */
-                    string16 /* source id */ )
+                    base::string16 /* source id */ )
 
 // Sent by the renderer process to indicate that a plugin instance has crashed.
 // Note: |plugin_pid| should not be trusted. The corresponding process has
@@ -2049,11 +2049,11 @@ IPC_MESSAGE_ROUTED2(ViewHostMsg_CrashedPlugin,
 // page. Replies true if yes, false otherwise, the reply string is ignored,
 // but is included so that we can use OnJavaScriptMessageBoxClosed.
 IPC_SYNC_MESSAGE_ROUTED3_2(ViewHostMsg_RunBeforeUnloadConfirm,
-                           GURL,     /* in - originating frame URL */
-                           string16  /* in - alert message */,
-                           bool      /* in - is a reload */,
-                           bool      /* out - success */,
-                           string16  /* out - This is ignored.*/)
+                           GURL,           /* in - originating frame URL */
+                           base::string16  /* in - alert message */,
+                           bool            /* in - is a reload */,
+                           bool            /* out - success */,
+                           base::string16  /* out - This is ignored.*/)
 
 // Sent when a provisional load on the main frame redirects.
 IPC_MESSAGE_ROUTED3(ViewHostMsg_DidRedirectProvisionalLoad,
@@ -2152,7 +2152,7 @@ IPC_MESSAGE_ROUTED0(ViewHostMsg_JSOutOfMemory)
 IPC_MESSAGE_ROUTED4(ViewHostMsg_RegisterProtocolHandler,
                     std::string /* scheme */,
                     GURL /* url */,
-                    string16 /* title */,
+                    base::string16 /* title */,
                     bool /* user_gesture */)
 
 // Stores new inspector setting in the profile.
@@ -2343,7 +2343,7 @@ IPC_MESSAGE_ROUTED0(ViewHostMsg_StartPluginIme)
 // for details.
 IPC_SYNC_MESSAGE_CONTROL2_0(ViewHostMsg_PreCacheFontCharacters,
                             LOGFONT /* font_data */,
-                            string16 /* characters */)
+                            base::string16 /* characters */)
 #endif
 
 #if defined(OS_POSIX)
diff --git a/content/common/worker_messages.h b/content/common/worker_messages.h
index e50099d5..6145f80 100644
--- a/content/common/worker_messages.h
+++ b/content/common/worker_messages.h
@@ -31,15 +31,15 @@ IPC_STRUCT_BEGIN(WorkerHostMsg_PostConsoleMessageToWorkerObject_Params)
   IPC_STRUCT_MEMBER(int, source_identifier)
   IPC_STRUCT_MEMBER(int, message_type)
   IPC_STRUCT_MEMBER(int, message_level)
-  IPC_STRUCT_MEMBER(string16, message)
+  IPC_STRUCT_MEMBER(base::string16, message)
   IPC_STRUCT_MEMBER(int, line_number)
-  IPC_STRUCT_MEMBER(string16, source_url)
+  IPC_STRUCT_MEMBER(base::string16, source_url)
 IPC_STRUCT_END()
 
 // Parameter structure for WorkerProcessMsg_CreateWorker.
 IPC_STRUCT_BEGIN(WorkerProcessMsg_CreateWorker_Params)
   IPC_STRUCT_MEMBER(GURL, url)
-  IPC_STRUCT_MEMBER(string16, name)
+  IPC_STRUCT_MEMBER(base::string16, name)
   IPC_STRUCT_MEMBER(int, route_id)
   IPC_STRUCT_MEMBER(int, creator_process_id)
   IPC_STRUCT_MEMBER(int64, shared_worker_appcache_id)
@@ -62,8 +62,8 @@ IPC_MESSAGE_CONTROL1(WorkerProcessMsg_CreateWorker,
 IPC_SYNC_MESSAGE_CONTROL5_1(WorkerProcessHostMsg_AllowDatabase,
                             int /* worker_route_id */,
                             GURL /* origin url */,
-                            string16 /* database name */,
-                            string16 /* database display name */,
+                            base::string16 /* database name */,
+                            base::string16 /* database display name */,
                             unsigned long /* estimated size */,
                             bool /* result */)
 
@@ -77,7 +77,7 @@ IPC_SYNC_MESSAGE_CONTROL2_1(WorkerProcessHostMsg_AllowFileSystem,
 IPC_SYNC_MESSAGE_CONTROL3_1(WorkerProcessHostMsg_AllowIndexedDB,
                             int /* worker_route_id */,
                             GURL /* origin url */,
-                            string16 /* database name */,
+                            base::string16 /* database name */,
                             bool /* result */)
 
 // Sent by the worker process to request being killed.
@@ -89,9 +89,9 @@ IPC_SYNC_MESSAGE_CONTROL0_0(WorkerProcessHostMsg_ForceKillWorker)
 // These are messages sent from the renderer process to the worker process.
 IPC_MESSAGE_ROUTED5(WorkerMsg_StartWorkerContext,
                     GURL /* url */,
-                    string16  /* user_agent */,
-                    string16  /* source_code */,
-                    string16  /* content_security_policy */,
+                    base::string16  /* user_agent */,
+                    base::string16  /* source_code */,
+                    base::string16  /* content_security_policy */,
                     blink::WebContentSecurityPolicyType)
 
 IPC_MESSAGE_ROUTED0(WorkerMsg_TerminateWorkerContext)
diff --git a/content/plugin/plugin_thread.cc b/content/plugin/plugin_thread.cc
index 528d513..72fd3cb 100644
--- a/content/plugin/plugin_thread.cc
+++ b/content/plugin/plugin_thread.cc
@@ -123,7 +123,7 @@ PluginThread::PluginThread()
   }
 
   GetContentClient()->plugin()->PluginProcessStarted(
-      plugin.get() ? plugin->plugin_info().name : string16());
+      plugin.get() ? plugin->plugin_info().name : base::string16());
 
   // Certain plugins, such as flash, steal the unhandled exception filter
   // thus we never get crash reports when they fault. This call fixes it.
diff --git a/content/plugin/webplugin_delegate_stub.cc b/content/plugin/webplugin_delegate_stub.cc
index c31ae2a..fd4827d 100644
--- a/content/plugin/webplugin_delegate_stub.cc
+++ b/content/plugin/webplugin_delegate_stub.cc
@@ -317,7 +317,8 @@ void WebPluginDelegateStub::OnGetPluginScriptableObject(int* route_id) {
   WebBindings::releaseObject(object);
 }
 
-void WebPluginDelegateStub::OnGetFormValue(string16* value, bool* success) {
+void WebPluginDelegateStub::OnGetFormValue(base::string16* value,
+                                           bool* success) {
   *success = false;
   if (!delegate_)
     return;
@@ -338,7 +339,7 @@ void WebPluginDelegateStub::OnSetContentAreaFocus(bool has_focus) {
 
 #if defined(OS_WIN) && !defined(USE_AURA)
 void WebPluginDelegateStub::OnImeCompositionUpdated(
-    const string16& text,
+    const base::string16& text,
     const std::vector<int>& clauses,
     const std::vector<int>& target,
     int cursor_position) {
@@ -349,7 +350,8 @@ void WebPluginDelegateStub::OnImeCompositionUpdated(
 #endif
 }
 
-void WebPluginDelegateStub::OnImeCompositionCompleted(const string16& text) {
+void WebPluginDelegateStub::OnImeCompositionCompleted(
+    const base::string16& text) {
   if (delegate_)
     delegate_->ImeCompositionCompleted(text);
 }
@@ -382,7 +384,8 @@ void WebPluginDelegateStub::OnWindowFrameChanged(const gfx::Rect& window_frame,
     delegate_->WindowFrameChanged(window_frame, view_frame);
 }
 
-void WebPluginDelegateStub::OnImeCompositionCompleted(const string16& text) {
+void WebPluginDelegateStub::OnImeCompositionCompleted(
+    const base::string16& text) {
   if (delegate_)
     delegate_->ImeCompositionCompleted(text);
 }
diff --git a/content/plugin/webplugin_delegate_stub.h b/content/plugin/webplugin_delegate_stub.h
index 09bcf3d..8787f25 100644
--- a/content/plugin/webplugin_delegate_stub.h
+++ b/content/plugin/webplugin_delegate_stub.h
@@ -79,15 +79,15 @@ class WebPluginDelegateStub : public IPC::Listener,
                               const std::string& result,
                               bool success,
                               int notify_id);
-  void OnGetFormValue(string16* value, bool* success);
+  void OnGetFormValue(base::string16* value, bool* success);
 
   void OnSetContentAreaFocus(bool has_focus);
 #if defined(OS_WIN) && !defined(USE_AURA)
-  void OnImeCompositionUpdated(const string16& text,
+  void OnImeCompositionUpdated(const base::string16& text,
                                const std::vector<int>& clauses,
                                const std::vector<int>& target,
                                int cursor_position);
-  void OnImeCompositionCompleted(const string16& text);
+  void OnImeCompositionCompleted(const base::string16& text);
 #endif
 #if defined(OS_MACOSX)
   void OnSetWindowFocus(bool has_focus);
@@ -96,7 +96,7 @@ class WebPluginDelegateStub : public IPC::Listener,
                         bool has_focus);
   void OnWindowFrameChanged(const gfx::Rect& window_frame,
                             const gfx::Rect& view_frame);
-  void OnImeCompositionCompleted(const string16& text);
+  void OnImeCompositionCompleted(const base::string16& text);
 #endif
 
   void OnDidReceiveManualResponse(
diff --git a/content/port/browser/render_widget_host_view_port.h b/content/port/browser/render_widget_host_view_port.h
index c8774a1..a668af6 100644
--- a/content/port/browser/render_widget_host_view_port.h
+++ b/content/port/browser/render_widget_host_view_port.h
@@ -146,10 +146,10 @@ class CONTENT_EXPORT RenderWidgetHostViewPort : public RenderWidgetHostView,
 
   // Tells the View that the tooltip text for the current mouse position over
   // the page has changed.
-  virtual void SetTooltipText(const string16& tooltip_text) = 0;
+  virtual void SetTooltipText(const base::string16& tooltip_text) = 0;
 
   // Notifies the View that the renderer text selection has changed.
-  virtual void SelectionChanged(const string16& text,
+  virtual void SelectionChanged(const base::string16& text,
                                 size_t offset,
                                 const gfx::Range& range) = 0;
 
diff --git a/content/port/browser/web_contents_view_port.h b/content/port/browser/web_contents_view_port.h
index 12c3083..fef0b3c 100644
--- a/content/port/browser/web_contents_view_port.h
+++ b/content/port/browser/web_contents_view_port.h
@@ -35,7 +35,7 @@ class CONTENT_EXPORT WebContentsViewPort : public WebContentsView {
   // is not strictly necessary and isn't expected to be displayed anywhere, but
   // can aid certain debugging tools such as Spy++ on Windows where you are
   // trying to find a specific window.
-  virtual void SetPageTitle(const string16& title) = 0;
+  virtual void SetPageTitle(const base::string16& title) = 0;
 
   // Invoked when the WebContents is notified that the RenderView has been
   // fully created.
diff --git a/content/public/browser/access_token_store.h b/content/public/browser/access_token_store.h
index 0af3fe7..bd13014 100644
--- a/content/public/browser/access_token_store.h
+++ b/content/public/browser/access_token_store.h
@@ -33,7 +33,7 @@ namespace content {
 class AccessTokenStore : public base::RefCountedThreadSafe<AccessTokenStore> {
  public:
   // Map of server URLs to associated access token.
-  typedef std::map<GURL, string16> AccessTokenSet;
+  typedef std::map<GURL, base::string16> AccessTokenSet;
   typedef base::Callback<void(AccessTokenSet, net::URLRequestContextGetter*)>
       LoadAccessTokensCallbackType;
 
@@ -47,7 +47,7 @@ class AccessTokenStore : public base::RefCountedThreadSafe<AccessTokenStore> {
       const LoadAccessTokensCallbackType& callback) = 0;
 
   virtual void SaveAccessToken(
-      const GURL& server_url, const string16& access_token) = 0;
+      const GURL& server_url, const base::string16& access_token) = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<AccessTokenStore>;
diff --git a/content/public/browser/browser_child_process_host.h b/content/public/browser/browser_child_process_host.h
index e618ad7..7776a0d 100644
--- a/content/public/browser/browser_child_process_host.h
+++ b/content/public/browser/browser_child_process_host.h
@@ -68,7 +68,7 @@ class CONTENT_EXPORT BrowserChildProcessHost : public IPC::Sender {
       bool known_dead, int* exit_code) = 0;
 
   // Sets the user-visible name of the process.
-  virtual void SetName(const string16& name) = 0;
+  virtual void SetName(const base::string16& name) = 0;
 
   // Set the handle of the process. BrowserChildProcessHost will do this when
   // the Launch method is used to start the process. However if the owner
diff --git a/content/public/browser/browser_plugin_guest_delegate.h b/content/public/browser/browser_plugin_guest_delegate.h
index e8767e2..fd535df 100644
--- a/content/public/browser/browser_plugin_guest_delegate.h
+++ b/content/public/browser/browser_plugin_guest_delegate.h
@@ -26,9 +26,9 @@ class CONTENT_EXPORT BrowserPluginGuestDelegate {
 
   // Add a message to the console.
   virtual void AddMessageToConsole(int32 level,
-                                   const string16& message,
+                                   const base::string16& message,
                                    int32 line_no,
-                                   const string16& source_id) {}
+                                   const base::string16& source_id) {}
 
   // Request the delegate to close this guest, and do whatever cleanup it needs
   // to do.
diff --git a/content/public/browser/child_process_data.h b/content/public/browser/child_process_data.h
index b669305..3683be9 100644
--- a/content/public/browser/child_process_data.h
+++ b/content/public/browser/child_process_data.h
@@ -18,7 +18,7 @@ struct ChildProcessData {
 
   // The name of the process.  i.e. for plugins it might be Flash, while for
   // for workers it might be the domain that it's from.
-  string16 name;
+  base::string16 name;
 
   // The unique identifier for this child process. This identifier is NOT a
   // process ID, and will be unique for all types of child process for
diff --git a/content/public/browser/content_browser_client.cc b/content/public/browser/content_browser_client.cc
index f105cc9..b404a97 100644
--- a/content/public/browser/content_browser_client.cc
+++ b/content/public/browser/content_browser_client.cc
@@ -141,8 +141,8 @@ bool ContentBrowserClient::AllowSaveLocalState(ResourceContext* context) {
 
 bool ContentBrowserClient::AllowWorkerDatabase(
     const GURL& url,
-    const string16& name,
-    const string16& display_name,
+    const base::string16& name,
+    const base::string16& display_name,
     unsigned long estimated_size,
     ResourceContext* context,
     const std::vector<std::pair<int, int> >& render_views) {
@@ -158,7 +158,7 @@ bool ContentBrowserClient::AllowWorkerFileSystem(
 
 bool ContentBrowserClient::AllowWorkerIndexedDB(
     const GURL& url,
-    const string16& name,
+    const base::string16& name,
     ResourceContext* context,
     const std::vector<std::pair<int, int> >& render_views) {
   return true;
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index bd3dc81..aae30eb 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -314,8 +314,8 @@ class CONTENT_EXPORT ContentBrowserClient {
   // This is called on the IO thread.
   virtual bool AllowWorkerDatabase(
       const GURL& url,
-      const string16& name,
-      const string16& display_name,
+      const base::string16& name,
+      const base::string16& display_name,
       unsigned long estimated_size,
       ResourceContext* context,
       const std::vector<std::pair<int, int> >& render_views);
@@ -333,7 +333,7 @@ class CONTENT_EXPORT ContentBrowserClient {
   // This is called on the IO thread.
   virtual bool AllowWorkerIndexedDB(
       const GURL& url,
-      const string16& name,
+      const base::string16& name,
       ResourceContext* context,
       const std::vector<std::pair<int, int> >& render_views);
 
diff --git a/content/public/browser/download_save_info.h b/content/public/browser/download_save_info.h
index 6b7a14a..1f44911 100644
--- a/content/public/browser/download_save_info.h
+++ b/content/public/browser/download_save_info.h
@@ -27,7 +27,7 @@ struct CONTENT_EXPORT DownloadSaveInfo {
 
   // If non-empty, contains an untrusted filename suggestion. This can't contain
   // a path (only a filename), and is only effective if |file_path| is empty.
-  string16 suggested_name;
+  base::string16 suggested_name;
 
   // If non-NULL, contains the source data stream for the file contents.
   scoped_ptr<net::FileStream> file_stream;
diff --git a/content/public/browser/download_url_parameters.h b/content/public/browser/download_url_parameters.h
index a907f09..b48bc2a 100644
--- a/content/public/browser/download_url_parameters.h
+++ b/content/public/browser/download_url_parameters.h
@@ -89,7 +89,7 @@ class CONTENT_EXPORT DownloadUrlParameters {
   void set_file_path(const base::FilePath& file_path) {
     save_info_.file_path = file_path;
   }
-  void set_suggested_name(const string16& suggested_name) {
+  void set_suggested_name(const base::string16& suggested_name) {
     save_info_.suggested_name = suggested_name;
   }
   void set_offset(int64 offset) { save_info_.offset = offset; }
@@ -126,7 +126,9 @@ class CONTENT_EXPORT DownloadUrlParameters {
     return resource_context_;
   }
   const base::FilePath& file_path() const { return save_info_.file_path; }
-  const string16& suggested_name() const { return save_info_.suggested_name; }
+  const base::string16& suggested_name() const {
+    return save_info_.suggested_name;
+  }
   int64 offset() const { return save_info_.offset; }
   const std::string& hash_state() const { return save_info_.hash_state; }
   bool prompt() const { return save_info_.prompt_for_save_location; }
diff --git a/content/public/browser/javascript_dialog_manager.cc b/content/public/browser/javascript_dialog_manager.cc
index 0a58d9f..ccc1f16 100644
--- a/content/public/browser/javascript_dialog_manager.cc
+++ b/content/public/browser/javascript_dialog_manager.cc
@@ -9,7 +9,7 @@ namespace content {
 bool JavaScriptDialogManager::HandleJavaScriptDialog(
     WebContents* web_contents,
     bool accept,
-    const string16* prompt_override) {
+    const base::string16* prompt_override) {
   return false;
 }
 
diff --git a/content/public/browser/javascript_dialog_manager.h b/content/public/browser/javascript_dialog_manager.h
index 778893d..cdc628b 100644
--- a/content/public/browser/javascript_dialog_manager.h
+++ b/content/public/browser/javascript_dialog_manager.h
@@ -23,7 +23,7 @@ class WebContents;
 class CONTENT_EXPORT JavaScriptDialogManager {
  public:
   typedef base::Callback<void(bool /* success */,
-                              const string16& /* user_input */)>
+                              const base::string16& /* user_input */)>
                                   DialogClosedCallback;
 
   // Displays a JavaScript dialog. |did_suppress_message| will not be nil; if
@@ -33,14 +33,14 @@ class CONTENT_EXPORT JavaScriptDialogManager {
       const GURL& origin_url,
       const std::string& accept_lang,
       JavaScriptMessageType javascript_message_type,
-      const string16& message_text,
-      const string16& default_prompt_text,
+      const base::string16& message_text,
+      const base::string16& default_prompt_text,
       const DialogClosedCallback& callback,
       bool* did_suppress_message) = 0;
 
   // Displays a dialog asking the user if they want to leave a page.
   virtual void RunBeforeUnloadDialog(WebContents* web_contents,
-                                     const string16& message_text,
+                                     const base::string16& message_text,
                                      bool is_reload,
                                      const DialogClosedCallback& callback) = 0;
 
@@ -50,7 +50,7 @@ class CONTENT_EXPORT JavaScriptDialogManager {
   // dialog was handled.
   virtual bool HandleJavaScriptDialog(WebContents* web_contents,
                                       bool accept,
-                                      const string16* prompt_override);
+                                      const base::string16* prompt_override);
 
   // Cancels all active and pending dialogs for the given WebContents.
   virtual void CancelActiveAndPendingDialogs(WebContents* web_contents) = 0;
diff --git a/content/public/browser/navigation_entry.h b/content/public/browser/navigation_entry.h
index 1c7d343..e23773f 100644
--- a/content/public/browser/navigation_entry.h
+++ b/content/public/browser/navigation_entry.h
@@ -73,8 +73,8 @@ class NavigationEntry {
   // The caller is responsible for detecting when there is no title and
   // displaying the appropriate "Untitled" label if this is being displayed to
   // the user.
-  virtual void SetTitle(const string16& title) = 0;
-  virtual const string16& GetTitle() const = 0;
+  virtual void SetTitle(const base::string16& title) = 0;
+  virtual const base::string16& GetTitle() const = 0;
 
   // Page state is an opaque blob created by Blink that represents the state of
   // the page. This includes form entries and scroll position for each frame.
@@ -99,7 +99,7 @@ class NavigationEntry {
   // the page if it is available or the URL. |languages| is the list of
   // accpeted languages (e.g., prefs::kAcceptLanguages) or empty if proper
   // URL formatting isn't needed (e.g., unit tests).
-  virtual const string16& GetTitleForDisplay(
+  virtual const base::string16& GetTitleForDisplay(
       const std::string& languages) const = 0;
 
   // Returns true if the current tab is in view source mode. This will be false
@@ -192,9 +192,11 @@ class NavigationEntry {
 
   // Set extra data on this NavigationEntry according to the specified |key|.
   // This data is not persisted by default.
-  virtual void SetExtraData(const std::string& key, const string16& data) = 0;
+  virtual void SetExtraData(const std::string& key,
+                            const base::string16& data) = 0;
   // If present, fills the |data| present at the specified |key|.
-  virtual bool GetExtraData(const std::string& key, string16* data) const = 0;
+  virtual bool GetExtraData(const std::string& key,
+                            base::string16* data) const = 0;
   // Removes the data at the specified |key|.
   virtual void ClearExtraData(const std::string& key) = 0;
 
diff --git a/content/public/browser/plugin_service.h b/content/public/browser/plugin_service.h
index 8c28948..76e6dda 100644
--- a/content/public/browser/plugin_service.h
+++ b/content/public/browser/plugin_service.h
@@ -89,7 +89,7 @@ class PluginService {
   // Returns the display name for the plugin identified by the given path. If
   // the path doesn't identify a plugin, or the plugin has no display name,
   // this will attempt to generate a display name from the path.
-  virtual string16 GetPluginDisplayNameByPath(
+  virtual base::string16 GetPluginDisplayNameByPath(
       const base::FilePath& plugin_path) = 0;
 
   // Asynchronously loads plugins if necessary and then calls back to the
diff --git a/content/public/browser/render_view_host.h b/content/public/browser/render_view_host.h
index 2eed287..366ad0d 100644
--- a/content/public/browser/render_view_host.h
+++ b/content/public/browser/render_view_host.h
@@ -102,7 +102,7 @@ class CONTENT_EXPORT RenderViewHost : virtual public RenderWidgetHost {
       int callback_context) = 0;
   virtual void DesktopNotificationPostDisplay(int callback_context) = 0;
   virtual void DesktopNotificationPostError(int notification_id,
-                                    const string16& message) = 0;
+                                    const base::string16& message) = 0;
   virtual void DesktopNotificationPostClose(int notification_id,
                                             bool by_user) = 0;
   virtual void DesktopNotificationPostClick(int notification_id) = 0;
@@ -170,15 +170,15 @@ class CONTENT_EXPORT RenderViewHost : virtual public RenderWidgetHost {
       const blink::WebMediaPlayerAction& action) = 0;
 
   // Runs some javascript within the context of a frame in the page.
-  virtual void ExecuteJavascriptInWebFrame(const string16& frame_xpath,
-                                           const string16& jscript) = 0;
+  virtual void ExecuteJavascriptInWebFrame(const base::string16& frame_xpath,
+                                           const base::string16& jscript) = 0;
 
   // Runs some javascript within the context of a frame in the page. The result
   // is sent back via the provided callback.
   typedef base::Callback<void(const base::Value*)> JavascriptResultCallback;
   virtual void ExecuteJavascriptInWebFrameCallbackResult(
-      const string16& frame_xpath,
-      const string16& jscript,
+      const base::string16& frame_xpath,
+      const base::string16& jscript,
       const JavascriptResultCallback& callback) = 0;
 
   // Tells the renderer to perform the given action on the plugin located at
@@ -190,7 +190,7 @@ class CONTENT_EXPORT RenderViewHost : virtual public RenderWidgetHost {
   virtual void ExitFullscreen() = 0;
 
   // Finds text on a page.
-  virtual void Find(int request_id, const string16& search_text,
+  virtual void Find(int request_id, const base::string16& search_text,
                     const blink::WebFindOptions& options) = 0;
 
   // Notifies the renderer that the user has closed the FindInPage window
@@ -223,7 +223,7 @@ class CONTENT_EXPORT RenderViewHost : virtual public RenderWidgetHost {
 
   // Requests the renderer to evaluate an xpath to a frame and insert css
   // into that frame's document.
-  virtual void InsertCSS(const string16& frame_xpath,
+  virtual void InsertCSS(const base::string16& frame_xpath,
                          const std::string& css) = 0;
 
   // Returns true if the RenderView is active and has not crashed. Virtual
diff --git a/content/public/browser/render_widget_host.h b/content/public/browser/render_widget_host.h
index 25fa41e..944ecbb 100644
--- a/content/public/browser/render_widget_host.h
+++ b/content/public/browser/render_widget_host.h
@@ -256,11 +256,11 @@ class CONTENT_EXPORT RenderWidgetHost : public IPC::Sender {
 
   // Makes an IPC call to tell webkit to replace the currently selected word
   // or a word around the cursor.
-  virtual void Replace(const string16& word) = 0;
+  virtual void Replace(const base::string16& word) = 0;
 
   // Makes an IPC call to tell webkit to replace the misspelling in the current
   // selection.
-  virtual void ReplaceMisspelling(const string16& word) = 0;
+  virtual void ReplaceMisspelling(const base::string16& word) = 0;
 
   // Called to notify the RenderWidget that the resize rect has changed without
   // the size of the RenderWidget itself changing.
diff --git a/content/public/browser/render_widget_host_view.h b/content/public/browser/render_widget_host_view.h
index 6caba6d..d815cdf 100644
--- a/content/public/browser/render_widget_host_view.h
+++ b/content/public/browser/render_widget_host_view.h
@@ -105,7 +105,7 @@ class CONTENT_EXPORT RenderWidgetHostView {
   virtual void SetShowingContextMenu(bool showing) = 0;
 
   // Returns the currently selected text.
-  virtual string16 GetSelectedText() const = 0;
+  virtual base::string16 GetSelectedText() const = 0;
 
   // Subclasses should override this method to do what is appropriate to set
   // the custom background for their platform.
diff --git a/content/public/browser/speech_recognition_manager.h b/content/public/browser/speech_recognition_manager.h
index c6dacea..f6a76a2 100644
--- a/content/public/browser/speech_recognition_manager.h
+++ b/content/public/browser/speech_recognition_manager.h
@@ -80,7 +80,7 @@ class SpeechRecognitionManager {
 
   // Returns a human readable string for the model/make of the active audio
   // input device for this computer.
-  virtual string16 GetAudioInputDeviceModel() = 0;
+  virtual base::string16 GetAudioInputDeviceModel() = 0;
 
   // Invokes the platform provided microphone settings UI in a non-blocking way,
   // via the BrowserThread::FILE thread.
diff --git a/content/public/browser/web_contents.h b/content/public/browser/web_contents.h
index 070966e..9bb2c83 100644
--- a/content/public/browser/web_contents.h
+++ b/content/public/browser/web_contents.h
@@ -222,7 +222,7 @@ class WebContents : public PageNavigator,
   // Returns the current navigation properties, which if a navigation is
   // pending may be provisional (e.g., the navigation could result in a
   // download, in which case the URL would revert to what it was previously).
-  virtual const string16& GetTitle() const = 0;
+  virtual const base::string16& GetTitle() const = 0;
 
   // The max page ID for any page that the current SiteInstance has loaded in
   // this WebContents.  Page IDs are specific to a given SiteInstance and
@@ -250,7 +250,7 @@ class WebContents : public PageNavigator,
 
   // Return the current load state and the URL associated with it.
   virtual const net::LoadStateWithParam& GetLoadState() const = 0;
-  virtual const string16& GetLoadStateHost() const = 0;
+  virtual const base::string16& GetLoadStateHost() const = 0;
 
   // Return the upload progress.
   virtual uint64 GetUploadSize() const = 0;
diff --git a/content/public/browser/web_contents_delegate.cc b/content/public/browser/web_contents_delegate.cc
index f9e4951..63ad65b 100644
--- a/content/public/browser/web_contents_delegate.cc
+++ b/content/public/browser/web_contents_delegate.cc
@@ -41,9 +41,9 @@ bool WebContentsDelegate::ShouldSuppressDialogs() {
 
 bool WebContentsDelegate::AddMessageToConsole(WebContents* source,
                                               int32 level,
-                                              const string16& message,
+                                              const base::string16& message,
                                               int32 line_no,
-                                              const string16& source_id) {
+                                              const base::string16& source_id) {
   return false;
 }
 
@@ -125,7 +125,7 @@ bool WebContentsDelegate::ShouldCreateWebContents(
     WebContents* web_contents,
     int route_id,
     WindowContainerType window_container_type,
-    const string16& frame_name,
+    const base::string16& frame_name,
     const GURL& target_url,
     const std::string& partition_id,
     SessionStorageNamespace* session_storage_namespace) {
diff --git a/content/public/browser/web_contents_delegate.h b/content/public/browser/web_contents_delegate.h
index 18bd9ef..81faa6b 100644
--- a/content/public/browser/web_contents_delegate.h
+++ b/content/public/browser/web_contents_delegate.h
@@ -182,9 +182,9 @@ class CONTENT_EXPORT WebContentsDelegate {
   // will be used for the message.
   virtual bool AddMessageToConsole(WebContents* source,
                                    int32 level,
-                                   const string16& message,
+                                   const base::string16& message,
                                    int32 line_no,
-                                   const string16& source_id);
+                                   const base::string16& source_id);
 
   // Tells us that we've finished firing this tab's beforeunload event.
   // The proceed bool tells us whether the user chose to proceed closing the
@@ -298,7 +298,7 @@ class CONTENT_EXPORT WebContentsDelegate {
       WebContents* web_contents,
       int route_id,
       WindowContainerType window_container_type,
-      const string16& frame_name,
+      const base::string16& frame_name,
       const GURL& target_url,
       const std::string& partition_id,
       SessionStorageNamespace* session_storage_namespace);
@@ -307,7 +307,7 @@ class CONTENT_EXPORT WebContentsDelegate {
   // typically happens when popups are created.
   virtual void WebContentsCreated(WebContents* source_contents,
                                   int64 source_frame_id,
-                                  const string16& frame_name,
+                                  const base::string16& frame_name,
                                   const GURL& target_url,
                                   WebContents* new_contents) {}
 
@@ -371,7 +371,7 @@ class CONTENT_EXPORT WebContentsDelegate {
   virtual void RegisterProtocolHandler(WebContents* web_contents,
                                        const std::string& protocol,
                                        const GURL& url,
-                                       const string16& title,
+                                       const base::string16& title,
                                        bool user_gesture) {}
 
   // Result of string search in the page. This includes the number of matches
diff --git a/content/public/browser/web_contents_observer.h b/content/public/browser/web_contents_observer.h
index 5c7c935..469c9e5 100644
--- a/content/public/browser/web_contents_observer.h
+++ b/content/public/browser/web_contents_observer.h
@@ -126,7 +126,7 @@ class CONTENT_EXPORT WebContentsObserver : public IPC::Listener,
   // this signal without a prior DidStartProvisionalLoadForFrame signal.
   virtual void DidCommitProvisionalLoadForFrame(
       int64 frame_id,
-      const string16& frame_unique_name,
+      const base::string16& frame_unique_name,
       bool is_main_frame,
       const GURL& url,
       PageTransition transition_type,
@@ -134,11 +134,11 @@ class CONTENT_EXPORT WebContentsObserver : public IPC::Listener,
 
   // This method is invoked when the provisional load failed.
   virtual void DidFailProvisionalLoad(int64 frame_id,
-                                      const string16& frame_unique_name,
+                                      const base::string16& frame_unique_name,
                                       bool is_main_frame,
                                       const GURL& validated_url,
                                       int error_code,
-                                      const string16& error_description,
+                                      const base::string16& error_description,
                                       RenderViewHost* render_view_host) {}
 
   // If the provisional load corresponded to the main frame, this method is
@@ -184,7 +184,7 @@ class CONTENT_EXPORT WebContentsObserver : public IPC::Listener,
                            const GURL& validated_url,
                            bool is_main_frame,
                            int error_code,
-                           const string16& error_description,
+                           const base::string16& error_description,
                            RenderViewHost* render_view_host) {}
 
   // This method is invoked when content was loaded from an in-memory cache.
diff --git a/content/public/browser/web_drag_dest_delegate.h b/content/public/browser/web_drag_dest_delegate.h
index cca3d2e..a556b88 100644
--- a/content/public/browser/web_drag_dest_delegate.h
+++ b/content/public/browser/web_drag_dest_delegate.h
@@ -55,7 +55,7 @@ class WebDragDestDelegate {
   // drag. Not every drag will trigger these.
   virtual void OnReceiveDataFromGtk(GtkSelectionData* data) = 0;
   virtual void OnReceiveProcessedData(const GURL& url,
-                                      const string16& title) = 0;
+                                      const base::string16& title) = 0;
 #elif defined(USE_AURA)
   // Called at the start of every drag to supply the data associated with the
   // drag.
diff --git a/content/public/browser/web_ui.h b/content/public/browser/web_ui.h
index 3dad85c..5427673 100644
--- a/content/public/browser/web_ui.h
+++ b/content/public/browser/web_ui.h
@@ -41,7 +41,7 @@ class CONTENT_EXPORT WebUI {
 
   // Returns JavaScript code that, when executed, calls the function specified
   // by |function_name| with the arguments specified in |arg_list|.
-  static string16 GetJavascriptCall(
+  static base::string16 GetJavascriptCall(
       const std::string& function_name,
       const std::vector<const base::Value*>& arg_list);
 
@@ -60,8 +60,8 @@ class CONTENT_EXPORT WebUI {
   // Gets a custom tab title provided by the Web UI. If there is no title
   // override, the string will be empty which should trigger the default title
   // behavior for the tab.
-  virtual const string16& GetOverriddenTitle() const = 0;
-  virtual void OverrideTitle(const string16& title) = 0;
+  virtual const base::string16& GetOverriddenTitle() const = 0;
+  virtual void OverrideTitle(const base::string16& title) = 0;
 
   // Returns the transition type that should be used for link clicks on this
   // Web UI. This will default to LINK but may be overridden.
diff --git a/content/public/browser/web_ui_data_source.h b/content/public/browser/web_ui_data_source.h
index 8348de3..b5cc6d5 100644
--- a/content/public/browser/web_ui_data_source.h
+++ b/content/public/browser/web_ui_data_source.h
@@ -30,7 +30,8 @@ class WebUIDataSource {
                                  WebUIDataSource* source);
 
   // Adds a string keyed to its name to our dictionary.
-  virtual void AddString(const std::string& name, const string16& value) = 0;
+  virtual void AddString(const std::string& name,
+                         const base::string16& value) = 0;
 
   // Adds a string keyed to its name to our dictionary.
   virtual void AddString(const std::string& name, const std::string& value) = 0;
diff --git a/content/public/browser/web_ui_message_handler.h b/content/public/browser/web_ui_message_handler.h
index 18fdd94..20a6072 100644
--- a/content/public/browser/web_ui_message_handler.h
+++ b/content/public/browser/web_ui_message_handler.h
@@ -46,7 +46,7 @@ class CONTENT_EXPORT WebUIMessageHandler {
                                  double* out_value);
 
   // Extract a string value from a list Value.
-  static string16 ExtractStringValue(const base::ListValue* value);
+  static base::string16 ExtractStringValue(const base::ListValue* value);
 
   // This is where subclasses specify which messages they'd like to handle and
   // perform any additional initialization.. At this point web_ui() will return
diff --git a/content/public/browser/worker_service.h b/content/public/browser/worker_service.h
index 10740fa..7ce2bf4 100644
--- a/content/public/browser/worker_service.h
+++ b/content/public/browser/worker_service.h
@@ -31,7 +31,7 @@ class WorkerService {
 
   struct WorkerInfo {
     GURL url;
-    string16 name;
+    base::string16 name;
     int process_id;
     int route_id;
     base::ProcessHandle handle;
diff --git a/content/public/browser/worker_service_observer.h b/content/public/browser/worker_service_observer.h
index ff6c8ef..9c1e055 100644
--- a/content/public/browser/worker_service_observer.h
+++ b/content/public/browser/worker_service_observer.h
@@ -15,7 +15,7 @@ namespace content {
 class WorkerServiceObserver {
  public:
   virtual void WorkerCreated(const GURL& url,
-                             const string16& name,
+                             const base::string16& name,
                              int process_id,
                              int route_id) {}
   virtual void WorkerDestroyed(int process_id, int route_id) {}
diff --git a/content/public/common/content_client.cc b/content/public/common/content_client.cc
index d4d00c0..54db517 100644
--- a/content/public/common/content_client.cc
+++ b/content/public/common/content_client.cc
@@ -89,8 +89,8 @@ std::string ContentClient::GetUserAgent() const {
   return std::string();
 }
 
-string16 ContentClient::GetLocalizedString(int message_id) const {
-  return string16();
+base::string16 ContentClient::GetLocalizedString(int message_id) const {
+  return base::string16();
 }
 
 base::StringPiece ContentClient::GetDataResource(
diff --git a/content/public/common/content_client.h b/content/public/common/content_client.h
index e2e0c73..1695656 100644
--- a/content/public/common/content_client.h
+++ b/content/public/common/content_client.h
@@ -118,7 +118,7 @@ class CONTENT_EXPORT ContentClient {
   virtual std::string GetUserAgent() const;
 
   // Returns a string resource given its id.
-  virtual string16 GetLocalizedString(int message_id) const;
+  virtual base::string16 GetLocalizedString(int message_id) const;
 
   // Return the contents of a resource in a StringPiece given the resource id.
   virtual base::StringPiece GetDataResource(
diff --git a/content/public/common/context_menu_params.h b/content/public/common/context_menu_params.h
index 49bd74f..fe91439 100644
--- a/content/public/common/context_menu_params.h
+++ b/content/public/common/context_menu_params.h
@@ -62,7 +62,7 @@ struct CONTENT_EXPORT ContextMenuParams {
   // The text associated with the link. May be an empty string if the contents
   // of the link are an image.
   // Will be empty if link_url is empty.
-  string16 link_text;
+  base::string16 link_text;
 
   // The link URL to be used ONLY for "copy link address". We don't validate
   // this field in the frontend process.
@@ -99,11 +99,11 @@ struct CONTENT_EXPORT ContextMenuParams {
   int media_flags;
 
   // This is the text of the selection that the context menu was invoked on.
-  string16 selection_text;
+  base::string16 selection_text;
 
   // The misspelled word under the cursor, if any. Used to generate the
   // |dictionary_suggestions| list.
-  string16 misspelled_word;
+  base::string16 misspelled_word;
 
   // The identifier of the misspelling under the cursor, if any.
   uint32 misspelling_hash;
@@ -113,7 +113,7 @@ struct CONTENT_EXPORT ContextMenuParams {
   // by intercepting ViewHostMsg_ContextMenu in ResourceMessageFilter
   // and populating dictionary_suggestions if the type is EDITABLE
   // and the misspelled_word is not empty.
-  std::vector<string16> dictionary_suggestions;
+  std::vector<base::string16> dictionary_suggestions;
 
   // If editable, flag for whether node is speech-input enabled.
   bool speech_input_enabled;
diff --git a/content/public/common/file_chooser_params.h b/content/public/common/file_chooser_params.h
index 0c7f1e4..4604326 100644
--- a/content/public/common/file_chooser_params.h
+++ b/content/public/common/file_chooser_params.h
@@ -37,14 +37,14 @@ struct CONTENT_EXPORT FileChooserParams {
 
   // Title to be used for the dialog. This may be empty for the default title,
   // which will be either "Open" or "Save" depending on the mode.
-  string16 title;
+  base::string16 title;
 
   // Default file name to select in the dialog.
   base::FilePath default_file_name;
 
   // A list of valid lower-cased MIME types or file extensions specified in an
   // input element. It is used to restrict selectable files to such types.
-  std::vector<string16> accept_types;
+  std::vector<base::string16> accept_types;
 
 #if defined(OS_ANDROID)
   // See http://www.w3.org/TR/html-media-capture for more information.
diff --git a/content/public/common/show_desktop_notification_params.h b/content/public/common/show_desktop_notification_params.h
index d31f947..5ff4511 100644
--- a/content/public/common/show_desktop_notification_params.h
+++ b/content/public/common/show_desktop_notification_params.h
@@ -21,15 +21,15 @@ struct CONTENT_EXPORT ShowDesktopNotificationHostMsgParams {
 
   // Contents of the notification if is_html is false.
   GURL icon_url;
-  string16 title;
-  string16 body;
+  base::string16 title;
+  base::string16 body;
 
   // Directionality of the notification.
   blink::WebTextDirection direction;
 
   // ReplaceID if this notification should replace an existing one; may be
   // empty if no replacement is called for.
-  string16 replace_id;
+  base::string16 replace_id;
 
   // Notification ID for sending events back for this notification.
   int notification_id;
diff --git a/content/public/common/speech_recognition_result.h b/content/public/common/speech_recognition_result.h
index 78044e5..aa1a02c 100644
--- a/content/public/common/speech_recognition_result.h
+++ b/content/public/common/speech_recognition_result.h
@@ -14,12 +14,12 @@
 namespace content {
 
 struct SpeechRecognitionHypothesis {
-  string16 utterance;
+  base::string16 utterance;
   double confidence;
 
   SpeechRecognitionHypothesis() : confidence(0.0) {}
 
-  SpeechRecognitionHypothesis(const string16& utterance_value,
+  SpeechRecognitionHypothesis(const base::string16& utterance_value,
                               double confidence_value)
       : utterance(utterance_value),
         confidence(confidence_value) {
diff --git a/content/public/plugin/content_plugin_client.h b/content/public/plugin/content_plugin_client.h
index cff2ad5..f68c3ad 100644
--- a/content/public/plugin/content_plugin_client.h
+++ b/content/public/plugin/content_plugin_client.h
@@ -20,7 +20,7 @@ class CONTENT_EXPORT ContentPluginClient {
   virtual void PreSandboxInitialization() {}
 
   // Notifies that a plugin process has started.
-  virtual void PluginProcessStarted(const string16& plugin_name) {}
+  virtual void PluginProcessStarted(const base::string16& plugin_name) {}
 };
 
 }  // namespace content
diff --git a/content/public/renderer/content_renderer_client.h b/content/public/renderer/content_renderer_client.h
index a3a6e5b..4757a669 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -119,7 +119,7 @@ class CONTENT_EXPORT ContentRendererClient {
       const blink::WebURLError& error,
       const std::string& accept_languages,
       std::string* error_html,
-      string16* error_description) {}
+      base::string16* error_description) {}
 
   // Allows the embedder to control when media resources are loaded. Embedders
   // can run |closure| immediately if they don't wish to defer media resource
diff --git a/content/public/renderer/render_view.h b/content/public/renderer/render_view.h
index 01857c7..b2e3045 100644
--- a/content/public/renderer/render_view.h
+++ b/content/public/renderer/render_view.h
@@ -95,8 +95,8 @@ class CONTENT_EXPORT RenderView : public IPC::Sender {
       const blink::WebPluginParams& params) = 0;
 
   // Evaluates a string of JavaScript in a particular frame.
-  virtual void EvaluateScript(const string16& frame_xpath,
-                              const string16& jscript,
+  virtual void EvaluateScript(const base::string16& frame_xpath,
+                              const base::string16& jscript,
                               int id,
                               bool notify_result) = 0;
 
diff --git a/content/public/test/browser_test_utils.cc b/content/public/test/browser_test_utils.cc
index 3894421..5a87327 100644
--- a/content/public/test/browser_test_utils.cc
+++ b/content/public/test/browser_test_utils.cc
@@ -539,21 +539,21 @@ bool SetCookie(BrowserContext* browser_context,
 }
 
 TitleWatcher::TitleWatcher(WebContents* web_contents,
-                           const string16& expected_title)
+                           const base::string16& expected_title)
     : WebContentsObserver(web_contents),
       message_loop_runner_(new MessageLoopRunner) {
   EXPECT_TRUE(web_contents != NULL);
   expected_titles_.push_back(expected_title);
 }
 
-void TitleWatcher::AlsoWaitForTitle(const string16& expected_title) {
+void TitleWatcher::AlsoWaitForTitle(const base::string16& expected_title) {
   expected_titles_.push_back(expected_title);
 }
 
 TitleWatcher::~TitleWatcher() {
 }
 
-const string16& TitleWatcher::WaitAndGetTitle() {
+const base::string16& TitleWatcher::WaitAndGetTitle() {
   message_loop_runner_->Run();
   return observed_title_;
 }
@@ -571,7 +571,7 @@ void TitleWatcher::TitleWasSet(NavigationEntry* entry, bool explicit_set) {
 }
 
 void TitleWatcher::TestTitle() {
-  std::vector<string16>::const_iterator it =
+  std::vector<base::string16>::const_iterator it =
       std::find(expected_titles_.begin(),
                 expected_titles_.end(),
                 web_contents()->GetTitle());
diff --git a/content/public/test/browser_test_utils.h b/content/public/test/browser_test_utils.h
index 53b40ec..510e809 100644
--- a/content/public/test/browser_test_utils.h
+++ b/content/public/test/browser_test_utils.h
@@ -196,16 +196,16 @@ class TitleWatcher : public WebContentsObserver {
   // entire lifetime of |this|. |expected_title| is the title that |this|
   // will wait for.
   TitleWatcher(WebContents* web_contents,
-               const string16& expected_title);
+               const base::string16& expected_title);
   virtual ~TitleWatcher();
 
   // Adds another title to watch for.
-  void AlsoWaitForTitle(const string16& expected_title);
+  void AlsoWaitForTitle(const base::string16& expected_title);
 
   // Waits until the title matches either expected_title or one of the titles
   // added with AlsoWaitForTitle. Returns the value of the most recently
   // observed matching title.
-  const string16& WaitAndGetTitle() WARN_UNUSED_RESULT;
+  const base::string16& WaitAndGetTitle() WARN_UNUSED_RESULT;
 
  private:
   // Overridden WebContentsObserver methods.
@@ -214,11 +214,11 @@ class TitleWatcher : public WebContentsObserver {
 
   void TestTitle();
 
-  std::vector<string16> expected_titles_;
+  std::vector<base::string16> expected_titles_;
   scoped_refptr<MessageLoopRunner> message_loop_runner_;
 
   // The most recently observed expected title, if any.
-  string16 observed_title_;
+  base::string16 observed_title_;
 
   DISALLOW_COPY_AND_ASSIGN(TitleWatcher);
 };
diff --git a/content/public/test/fake_speech_recognition_manager.cc b/content/public/test/fake_speech_recognition_manager.cc
index 065fcb5..3d7b582 100644
--- a/content/public/test/fake_speech_recognition_manager.cc
+++ b/content/public/test/fake_speech_recognition_manager.cc
@@ -115,8 +115,8 @@ void FakeSpeechRecognitionManager::AbortAllSessionsForRenderView(
 
 bool FakeSpeechRecognitionManager::HasAudioInputDevices() { return true; }
 
-string16 FakeSpeechRecognitionManager::GetAudioInputDeviceModel() {
-  return string16();
+base::string16 FakeSpeechRecognitionManager::GetAudioInputDeviceModel() {
+  return base::string16();
 }
 
 int FakeSpeechRecognitionManager::GetSession(int render_process_id,
diff --git a/content/public/test/fake_speech_recognition_manager.h b/content/public/test/fake_speech_recognition_manager.h
index 0973f6c..c76340a 100644
--- a/content/public/test/fake_speech_recognition_manager.h
+++ b/content/public/test/fake_speech_recognition_manager.h
@@ -52,7 +52,7 @@ class FakeSpeechRecognitionManager : public SpeechRecognitionManager {
   virtual void AbortAllSessionsForRenderView(int render_process_id,
                                              int render_view_id) OVERRIDE;
   virtual bool HasAudioInputDevices() OVERRIDE;
-  virtual string16 GetAudioInputDeviceModel() OVERRIDE;
+  virtual base::string16 GetAudioInputDeviceModel() OVERRIDE;
   virtual void ShowAudioInputSettings() OVERRIDE {}
   virtual int GetSession(int render_process_id,
                          int render_view_id,
diff --git a/content/public/test/mock_render_process_host.cc b/content/public/test/mock_render_process_host.cc
index 21bcaf2..9ef67e3 100644
--- a/content/public/test/mock_render_process_host.cc
+++ b/content/public/test/mock_render_process_host.cc
@@ -111,7 +111,7 @@ StoragePartition* MockRenderProcessHost::GetStoragePartition() const {
   return NULL;
 }
 
-void MockRenderProcessHost::AddWord(const string16& word) {
+void MockRenderProcessHost::AddWord(const base::string16& word) {
 }
 
 bool MockRenderProcessHost::FastShutdownIfPossible() {
diff --git a/content/public/test/mock_render_process_host.h b/content/public/test/mock_render_process_host.h
index 3836ff5..daf9c81 100644
--- a/content/public/test/mock_render_process_host.h
+++ b/content/public/test/mock_render_process_host.h
@@ -50,7 +50,7 @@ class MockRenderProcessHost : public RenderProcessHost {
   virtual int VisibleWidgetCount() const OVERRIDE;
   virtual bool IsGuest() const OVERRIDE;
   virtual StoragePartition* GetStoragePartition() const OVERRIDE;
-  virtual void AddWord(const string16& word);
+  virtual void AddWord(const base::string16& word);
   virtual bool FastShutdownIfPossible() OVERRIDE;
   virtual bool FastShutdownStarted() const OVERRIDE;
   virtual void DumpHandles() OVERRIDE;
diff --git a/content/public/test/mock_render_thread.cc b/content/public/test/mock_render_thread.cc
index 4862675..9da66ac 100644
--- a/content/public/test/mock_render_thread.cc
+++ b/content/public/test/mock_render_thread.cc
@@ -26,7 +26,7 @@ MockRenderThread::~MockRenderThread() {
 }
 
 void MockRenderThread::VerifyRunJavaScriptMessageSend(
-    const string16& expected_alert_message) {
+    const base::string16& expected_alert_message) {
   const IPC::Message* alert_msg =
       sink_.GetUniqueMessageMatching(ViewHostMsg_RunJavaScriptMessage::ID);
   ASSERT_TRUE(alert_msg);
diff --git a/content/public/test/mock_render_thread.h b/content/public/test/mock_render_thread.h
index ec03c78..dc5b82a 100644
--- a/content/public/test/mock_render_thread.h
+++ b/content/public/test/mock_render_thread.h
@@ -35,7 +35,8 @@ class MockRenderThread : public RenderThread {
 
   // Helpers for embedders to know when content IPC messages are received, since
   // they don't have access to content IPC files.
-  void VerifyRunJavaScriptMessageSend(const string16& expected_alert_message);
+  void VerifyRunJavaScriptMessageSend(
+      const base::string16& expected_alert_message);
 
   // RenderThread implementation:
   virtual bool Send(IPC::Message* msg) OVERRIDE;
diff --git a/content/public/test/render_view_test.cc b/content/public/test/render_view_test.cc
index 2d96a85..64a4d2c 100644
--- a/content/public/test/render_view_test.cc
+++ b/content/public/test/render_view_test.cc
@@ -91,7 +91,7 @@ void RenderViewTest::ExecuteJavaScript(const char* js) {
 }
 
 bool RenderViewTest::ExecuteJavaScriptAndReturnIntValue(
-    const string16& script,
+    const base::string16& script,
     int* int_result) {
   v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
   v8::Handle<v8::Value> result =
@@ -173,7 +173,7 @@ void RenderViewTest::SetUp() {
       kMainFrameRouteId,
       kSurfaceId,
       kInvalidSessionStorageNamespaceId,
-      string16(),
+      base::string16(),
       false, // is_renderer_created
       false, // swapped_out
       false, // hidden
diff --git a/content/public/test/render_view_test.h b/content/public/test/render_view_test.h
index 6a5c2a1..204d023 100644
--- a/content/public/test/render_view_test.h
+++ b/content/public/test/render_view_test.h
@@ -66,7 +66,8 @@ class RenderViewTest : public testing::Test {
   // |result|.
   // Returns true if the JavaScript was evaluated correctly to an int value,
   // false otherwise.
-  bool ExecuteJavaScriptAndReturnIntValue(const string16& script, int* result);
+  bool ExecuteJavaScriptAndReturnIntValue(const base::string16& script,
+                                          int* result);
 
   // Loads the given HTML into the main frame as a data: URL and blocks until
   // the navigation is committed.
diff --git a/content/public/test/test_renderer_host.h b/content/public/test/test_renderer_host.h
index 69cfa8f..5eb5777 100644
--- a/content/public/test/test_renderer_host.h
+++ b/content/public/test/test_renderer_host.h
@@ -69,7 +69,7 @@ class RenderViewHostTester {
   virtual ~RenderViewHostTester() {}
 
   // Gives tests access to RenderViewHostImpl::CreateRenderView.
-  virtual bool CreateRenderView(const string16& frame_name,
+  virtual bool CreateRenderView(const base::string16& frame_name,
                                 int opener_route_id,
                                 int32 max_page_id) = 0;
 
diff --git a/content/public/test/test_utils.cc b/content/public/test/test_utils.cc
index 989437c..c417483 100644
--- a/content/public/test/test_utils.cc
+++ b/content/public/test/test_utils.cc
@@ -137,7 +137,7 @@ scoped_ptr<base::Value> ExecuteScriptAndGetValue(
   ScriptCallback observer;
 
   render_view_host->ExecuteJavascriptInWebFrameCallbackResult(
-      string16(),  // frame_xpath,
+      base::string16(),  // frame_xpath,
       UTF8ToUTF16(script),
       base::Bind(&ScriptCallback::ResultCallback, base::Unretained(&observer)));
   base::MessageLoop* loop = base::MessageLoop::current();
diff --git a/content/renderer/android/address_detector.cc b/content/renderer/android/address_detector.cc
index afc7ab6..fdc70b1 100644
--- a/content/renderer/android/address_detector.cc
+++ b/content/renderer/android/address_detector.cc
@@ -36,20 +36,23 @@ size_t AddressDetector::GetMaximumContentLength() {
   return kMaxAddressLength;
 }
 
-std::string AddressDetector::GetContentText(const string16& text) {
+std::string AddressDetector::GetContentText(const base::string16& text) {
   // Get the address and replace unicode bullets with commas.
-  string16 address_16 = CollapseWhitespace(text, false);
+  base::string16 address_16 = CollapseWhitespace(text, false);
   std::replace(address_16.begin(), address_16.end(),
       static_cast<char16>(0x2022), static_cast<char16>(','));
   return UTF16ToUTF8(address_16);
 }
 
-bool AddressDetector::FindContent(const string16::const_iterator& begin,
-    const string16::const_iterator& end, size_t* start_pos, size_t* end_pos,
+bool AddressDetector::FindContent(
+    const base::string16::const_iterator& begin,
+    const base::string16::const_iterator& end,
+    size_t* start_pos,
+    size_t* end_pos,
     std::string* content_text) {
   if (address_parser::FindAddress(begin, end, start_pos, end_pos)) {
     content_text->assign(
-        GetContentText(string16(begin + *start_pos, begin + *end_pos)));
+        GetContentText(base::string16(begin + *start_pos, begin + *end_pos)));
     return true;
   }
   return false;
diff --git a/content/renderer/android/address_detector.h b/content/renderer/android/address_detector.h
index 2619503..eea777f 100644
--- a/content/renderer/android/address_detector.h
+++ b/content/renderer/android/address_detector.h
@@ -19,15 +19,15 @@ class AddressDetector : public ContentDetector {
 
  private:
   // Implementation of ContentDetector.
-  virtual bool FindContent(const string16::const_iterator& begin,
-                           const string16::const_iterator& end,
+  virtual bool FindContent(const base::string16::const_iterator& begin,
+                           const base::string16::const_iterator& end,
                            size_t* start_pos,
                            size_t* end_pos,
                            std::string* content_text) OVERRIDE;
   virtual GURL GetIntentURL(const std::string& content_text) OVERRIDE;
   virtual size_t GetMaximumContentLength() OVERRIDE;
 
-  std::string GetContentText(const string16& text);
+  std::string GetContentText(const base::string16& text);
 
   DISALLOW_COPY_AND_ASSIGN(AddressDetector);
 };
diff --git a/content/renderer/android/content_detector.cc b/content/renderer/android/content_detector.cc
index 66af041..e5d2f05 100644
--- a/content/renderer/android/content_detector.cc
+++ b/content/renderer/android/content_detector.cc
@@ -52,7 +52,7 @@ WebRange ContentDetector::FindContentRange(
   if (surrounding_text.isNull())
     return WebRange();
 
-  string16 content = surrounding_text.textContent();
+  base::string16 content = surrounding_text.textContent();
   if (content.empty())
     return WebRange();
 
diff --git a/content/renderer/android/content_detector.h b/content/renderer/android/content_detector.h
index 85ee668..28a153a 100644
--- a/content/renderer/android/content_detector.h
+++ b/content/renderer/android/content_detector.h
@@ -44,8 +44,8 @@ class ContentDetector {
   // if the desired content is found. The start and end positions relative to
   // the input iterators are returned in start_pos and end_pos.
   // The end position is assumed to be non-inclusive.
-  virtual bool FindContent(const string16::const_iterator& begin,
-                           const string16::const_iterator& end,
+  virtual bool FindContent(const base::string16::const_iterator& begin,
+                           const base::string16::const_iterator& end,
                            size_t* start_pos,
                            size_t* end_pos,
                            std::string* content_text) = 0;
diff --git a/content/renderer/android/email_detector.cc b/content/renderer/android/email_detector.cc
index 28b8af4..dba1f42 100644
--- a/content/renderer/android/email_detector.cc
+++ b/content/renderer/android/email_detector.cc
@@ -42,12 +42,12 @@ GURL EmailDetector::GetIntentURL(const std::string& content_text) {
       net::EscapeQueryParamValue(content_text, true));
 }
 
-bool EmailDetector::FindContent(const string16::const_iterator& begin,
-                                const string16::const_iterator& end,
+bool EmailDetector::FindContent(const base::string16::const_iterator& begin,
+                                const base::string16::const_iterator& end,
                                 size_t* start_pos,
                                 size_t* end_pos,
                                 std::string* content_text) {
-  string16 utf16_input = string16(begin, end);
+  base::string16 utf16_input = base::string16(begin, end);
   icu::UnicodeString pattern(kEmailRegex);
   icu::UnicodeString input(utf16_input.data(), utf16_input.length());
   UErrorCode status = U_ZERO_ERROR;
diff --git a/content/renderer/android/email_detector.h b/content/renderer/android/email_detector.h
index dbd6de3..ff469e8 100644
--- a/content/renderer/android/email_detector.h
+++ b/content/renderer/android/email_detector.h
@@ -23,8 +23,8 @@ class CONTENT_EXPORT EmailDetector : public ContentDetector {
   friend class EmailDetectorTest;
 
   // Implementation of ContentDetector.
-  virtual bool FindContent(const string16::const_iterator& begin,
-                           const string16::const_iterator& end,
+  virtual bool FindContent(const base::string16::const_iterator& begin,
+                           const base::string16::const_iterator& end,
                            size_t* start_pos,
                            size_t* end_pos,
                            std::string* content_text) OVERRIDE;
diff --git a/content/renderer/android/email_detector_unittest.cc b/content/renderer/android/email_detector_unittest.cc
index f3ed10f..45bcc9b 100644
--- a/content/renderer/android/email_detector_unittest.cc
+++ b/content/renderer/android/email_detector_unittest.cc
@@ -13,8 +13,8 @@ class EmailDetectorTest : public testing::Test {
  public:
   static void FindAndCheckEmail(const std::string& content,
                                 const std::string& expected) {
-    string16 content_16 = UTF8ToUTF16(content);
-    string16 result_16;
+    base::string16 content_16 = UTF8ToUTF16(content);
+    base::string16 result_16;
     size_t start, end;
     EmailDetector detector;
     std::string content_text;
diff --git a/content/renderer/android/phone_number_detector.cc b/content/renderer/android/phone_number_detector.cc
index 19c526f..843adfa 100644
--- a/content/renderer/android/phone_number_detector.cc
+++ b/content/renderer/android/phone_number_detector.cc
@@ -54,12 +54,13 @@ GURL PhoneNumberDetector::GetIntentURL(const std::string& content_text) {
       net::EscapeQueryParamValue(content_text, true));
 }
 
-bool PhoneNumberDetector::FindContent(const string16::const_iterator& begin,
-                                      const string16::const_iterator& end,
-                                      size_t* start_pos,
-                                      size_t* end_pos,
-                                      std::string* content_text) {
-  string16 utf16_input = string16(begin, end);
+bool PhoneNumberDetector::FindContent(
+    const base::string16::const_iterator& begin,
+    const base::string16::const_iterator& end,
+    size_t* start_pos,
+    size_t* end_pos,
+    std::string* content_text) {
+  base::string16 utf16_input = base::string16(begin, end);
   std::string utf8_input = UTF16ToUTF8(utf16_input);
 
   PhoneNumberMatcher matcher(utf8_input, region_code_);
diff --git a/content/renderer/android/phone_number_detector.h b/content/renderer/android/phone_number_detector.h
index 1ccf47d..081a427 100644
--- a/content/renderer/android/phone_number_detector.h
+++ b/content/renderer/android/phone_number_detector.h
@@ -24,8 +24,8 @@ class CONTENT_EXPORT PhoneNumberDetector : public ContentDetector {
   friend class PhoneNumberDetectorTest;
 
   // Implementation of ContentDetector.
-  virtual bool FindContent(const string16::const_iterator& begin,
-                           const string16::const_iterator& end,
+  virtual bool FindContent(const base::string16::const_iterator& begin,
+                           const base::string16::const_iterator& end,
                            size_t* start_pos,
                            size_t* end_pos,
                            std::string* content_text) OVERRIDE;
diff --git a/content/renderer/android/phone_number_detector_unittest.cc b/content/renderer/android/phone_number_detector_unittest.cc
index 387cede..e248f0e 100644
--- a/content/renderer/android/phone_number_detector_unittest.cc
+++ b/content/renderer/android/phone_number_detector_unittest.cc
@@ -13,8 +13,8 @@ class PhoneNumberDetectorTest : public testing::Test {
  public:
   static std::string FindNumber(const std::string& content,
                                 const std::string& region) {
-    string16 content_16 = UTF8ToUTF16(content);
-    string16 result_16;
+    base::string16 content_16 = UTF8ToUTF16(content);
+    base::string16 result_16;
     size_t start, end;
     PhoneNumberDetector detector(region);
     std::string content_text;
@@ -26,8 +26,8 @@ class PhoneNumberDetectorTest : public testing::Test {
 
   static std::string FindAndFormatNumber(const std::string& content,
                                          const std::string& region) {
-    string16 content_16 = UTF8ToUTF16(content);
-    string16 result_16;
+    base::string16 content_16 = UTF8ToUTF16(content);
+    base::string16 result_16;
     size_t start, end;
     PhoneNumberDetector detector(region);
     std::string content_text;
diff --git a/content/renderer/cpp_bound_class_unittest.cc b/content/renderer/cpp_bound_class_unittest.cc
index 0aeab77..8b05fea 100644
--- a/content/renderer/cpp_bound_class_unittest.cc
+++ b/content/renderer/cpp_bound_class_unittest.cc
@@ -104,7 +104,7 @@ class CppBoundClassTest : public RenderViewTest {
 
   void CheckTrue(const std::string& expression) {
     int was_page_a = -1;
-    string16 check_page_a =
+    base::string16 check_page_a =
         ASCIIToUTF16(std::string("Number(") + expression + ")");
     EXPECT_TRUE(ExecuteJavaScriptAndReturnIntValue(check_page_a, &was_page_a));
     EXPECT_EQ(1, was_page_a);
diff --git a/content/renderer/dom_storage/dom_storage_dispatcher.cc b/content/renderer/dom_storage/dom_storage_dispatcher.cc
index 936f217..477251c 100644
--- a/content/renderer/dom_storage/dom_storage_dispatcher.cc
+++ b/content/renderer/dom_storage/dom_storage_dispatcher.cc
@@ -111,12 +111,12 @@ class DomStorageDispatcher::ProxyImpl : public DOMStorageProxy {
   virtual void LoadArea(int connection_id, DOMStorageValuesMap* values,
                         bool* send_log_get_messages,
                         const CompletionCallback& callback) OVERRIDE;
-  virtual void SetItem(int connection_id, const string16& key,
-                       const string16& value, const GURL& page_url,
+  virtual void SetItem(int connection_id, const base::string16& key,
+                       const base::string16& value, const GURL& page_url,
                        const CompletionCallback& callback) OVERRIDE;
-  virtual void LogGetItem(int connection_id, const string16& key,
+  virtual void LogGetItem(int connection_id, const base::string16& key,
                           const base::NullableString16& value) OVERRIDE;
-  virtual void RemoveItem(int connection_id, const string16& key,
+  virtual void RemoveItem(int connection_id, const base::string16& key,
                           const GURL& page_url,
                           const CompletionCallback& callback) OVERRIDE;
   virtual void ClearArea(int connection_id,
@@ -244,8 +244,8 @@ void DomStorageDispatcher::ProxyImpl::LoadArea(
 }
 
 void DomStorageDispatcher::ProxyImpl::SetItem(
-    int connection_id, const string16& key,
-    const string16& value, const GURL& page_url,
+    int connection_id, const base::string16& key,
+    const base::string16& value, const GURL& page_url,
     const CompletionCallback& callback) {
   PushPendingCallback(callback);
   throttling_filter_->SendThrottled(new DOMStorageHostMsg_SetItem(
@@ -253,13 +253,13 @@ void DomStorageDispatcher::ProxyImpl::SetItem(
 }
 
 void DomStorageDispatcher::ProxyImpl::LogGetItem(
-    int connection_id, const string16& key,
+    int connection_id, const base::string16& key,
     const base::NullableString16& value) {
   sender_->Send(new DOMStorageHostMsg_LogGetItem(connection_id, key, value));
 }
 
 void DomStorageDispatcher::ProxyImpl::RemoveItem(
-    int connection_id, const string16& key,  const GURL& page_url,
+    int connection_id, const base::string16& key,  const GURL& page_url,
     const CompletionCallback& callback) {
   PushPendingCallback(callback);
   throttling_filter_->SendThrottled(new DOMStorageHostMsg_RemoveItem(
diff --git a/content/renderer/external_popup_menu_browsertest.cc b/content/renderer/external_popup_menu_browsertest.cc
index fd6041d..2e3e664 100644
--- a/content/renderer/external_popup_menu_browsertest.cc
+++ b/content/renderer/external_popup_menu_browsertest.cc
@@ -57,7 +57,7 @@ class ExternalPopupMenuTest : public RenderViewTest {
   }
 
   int GetSelectedIndex() {
-    string16 script(ASCIIToUTF16(kSelectID));
+    base::string16 script(ASCIIToUTF16(kSelectID));
     script.append(ASCIIToUTF16(".selectedIndex"));
     int selected_index = -1;
     ExecuteJavaScriptAndReturnIntValue(script, &selected_index);
diff --git a/content/renderer/geolocation_dispatcher.cc b/content/renderer/geolocation_dispatcher.cc
index 031376c..a764b61 100644
--- a/content/renderer/geolocation_dispatcher.cc
+++ b/content/renderer/geolocation_dispatcher.cc
@@ -87,7 +87,7 @@ bool GeolocationDispatcher::lastPosition(WebGeolocationPosition&) {
 void GeolocationDispatcher::requestPermission(
     const WebGeolocationPermissionRequest& permissionRequest) {
   int bridge_id = pending_permissions_->add(permissionRequest);
-  string16 origin = permissionRequest.securityOrigin().toString();
+  base::string16 origin = permissionRequest.securityOrigin().toString();
   Send(new GeolocationHostMsg_RequestPermission(
       routing_id(), bridge_id, GURL(origin)));
 }
@@ -99,7 +99,7 @@ void GeolocationDispatcher::cancelPermissionRequest(
   int bridge_id;
   if (!pending_permissions_->remove(permissionRequest, bridge_id))
     return;
-  string16 origin = permissionRequest.securityOrigin().toString();
+  base::string16 origin = permissionRequest.securityOrigin().toString();
   Send(new GeolocationHostMsg_CancelPermissionRequest(
       routing_id(), bridge_id, GURL(origin)));
 }
diff --git a/content/renderer/gpu/input_event_filter_unittest.cc b/content/renderer/gpu/input_event_filter_unittest.cc
index 93a0707..8630d15 100644
--- a/content/renderer/gpu/input_event_filter_unittest.cc
+++ b/content/renderer/gpu/input_event_filter_unittest.cc
@@ -285,9 +285,9 @@ TEST_F(InputEventFilterTest, PreserveRelativeOrder) {
   messages.push_back(InputMsg_Paste(kTestRoutingID));
   messages.push_back(InputMsg_PasteAndMatchStyle(kTestRoutingID));
   messages.push_back(InputMsg_Delete(kTestRoutingID));
-  messages.push_back(InputMsg_Replace(kTestRoutingID, string16()));
+  messages.push_back(InputMsg_Replace(kTestRoutingID, base::string16()));
   messages.push_back(InputMsg_ReplaceMisspelling(kTestRoutingID,
-                                                     string16()));
+                                                     base::string16()));
   messages.push_back(InputMsg_Delete(kTestRoutingID));
   messages.push_back(InputMsg_SelectAll(kTestRoutingID));
   messages.push_back(InputMsg_Unselect(kTestRoutingID));
diff --git a/content/renderer/java/java_bridge_dispatcher.cc b/content/renderer/java/java_bridge_dispatcher.cc
index 633295a..f7e435c 100644
--- a/content/renderer/java/java_bridge_dispatcher.cc
+++ b/content/renderer/java/java_bridge_dispatcher.cc
@@ -65,7 +65,7 @@ void JavaBridgeDispatcher::DidClearWindowObject(blink::WebFrame* web_frame) {
 }
 
 void JavaBridgeDispatcher::OnAddNamedObject(
-    const string16& name,
+    const base::string16& name,
     const NPVariant_Param& variant_param) {
   DCHECK_EQ(variant_param.type, NPVARIANT_PARAM_SENDER_OBJECT_ROUTING_ID);
 
@@ -95,7 +95,7 @@ void JavaBridgeDispatcher::OnAddNamedObject(
   objects_[name] = variant;
 }
 
-void JavaBridgeDispatcher::OnRemoveNamedObject(const string16& name) {
+void JavaBridgeDispatcher::OnRemoveNamedObject(const base::string16& name) {
   if (!channel_.get()) {
     DCHECK(objects_.empty());
     return;
diff --git a/content/renderer/java/java_bridge_dispatcher.h b/content/renderer/java/java_bridge_dispatcher.h
index a50eb38..325d529 100644
--- a/content/renderer/java/java_bridge_dispatcher.h
+++ b/content/renderer/java/java_bridge_dispatcher.h
@@ -33,15 +33,15 @@ class JavaBridgeDispatcher : public RenderViewObserver {
   virtual void DidClearWindowObject(blink::WebFrame* frame) OVERRIDE;
 
   // Message handlers
-  void OnAddNamedObject(const string16& name,
+  void OnAddNamedObject(const base::string16& name,
                         const NPVariant_Param& variant_param);
-  void OnRemoveNamedObject(const string16& name);
+  void OnRemoveNamedObject(const base::string16& name);
 
   void EnsureChannelIsSetUp();
 
   // Objects that will be bound to the window when the window object is next
   // cleared. We hold a ref to these.
-  typedef std::map<string16, NPVariant> ObjectMap;
+  typedef std::map<base::string16, NPVariant> ObjectMap;
   ObjectMap objects_;
   scoped_refptr<JavaBridgeChannel> channel_;
 };
diff --git a/content/renderer/media/midi_dispatcher.cc b/content/renderer/media/midi_dispatcher.cc
index e5dccf3..1f04e3e 100644
--- a/content/renderer/media/midi_dispatcher.cc
+++ b/content/renderer/media/midi_dispatcher.cc
@@ -48,7 +48,7 @@ void MIDIDispatcher::cancelSysExPermissionRequest(
        it.Advance()) {
     WebMIDIPermissionRequest* value = it.GetCurrentValue();
     if (value->equals(request)) {
-      string16 origin = request.securityOrigin().toString();
+      base::string16 origin = request.securityOrigin().toString();
       Send(new MIDIHostMsg_CancelSysExPermissionRequest(
           routing_id(), it.GetCurrentKey(), GURL(origin)));
       requests_.Remove(it.GetCurrentKey());
diff --git a/content/renderer/media/rtc_data_channel_handler.cc b/content/renderer/media/rtc_data_channel_handler.cc
index 3cd9a37..065048a 100644
--- a/content/renderer/media/rtc_data_channel_handler.cc
+++ b/content/renderer/media/rtc_data_channel_handler.cc
@@ -120,7 +120,7 @@ void RtcDataChannelHandler::OnMessage(const webrtc::DataBuffer& buffer) {
   if (buffer.binary) {
     webkit_client_->didReceiveRawData(buffer.data.data(), buffer.data.length());
   } else {
-    string16 utf16;
+    base::string16 utf16;
     if (!UTF8ToUTF16(buffer.data.data(), buffer.data.length(), &utf16)) {
       LOG(ERROR) << "Failed convert received data to UTF16";
       return;
diff --git a/content/renderer/media/webcontentdecryptionmodule_impl.cc b/content/renderer/media/webcontentdecryptionmodule_impl.cc
index 2c363ce..d320124 100644
--- a/content/renderer/media/webcontentdecryptionmodule_impl.cc
+++ b/content/renderer/media/webcontentdecryptionmodule_impl.cc
@@ -149,7 +149,7 @@ WebContentDecryptionModuleSessionImpl* ReferenceIdAdapter::GetSession(
 //------------------------------------------------------------------------------
 
 WebContentDecryptionModuleImpl*
-WebContentDecryptionModuleImpl::Create(const string16& key_system) {
+WebContentDecryptionModuleImpl::Create(const base::string16& key_system) {
   // TODO(ddorwin): Guard against this in supported types check and remove this.
   // Chromium only supports ASCII key systems.
   if (!IsStringASCII(key_system)) {
diff --git a/content/renderer/media/webcontentdecryptionmodule_impl.h b/content/renderer/media/webcontentdecryptionmodule_impl.h
index a457bca..27c79c0 100644
--- a/content/renderer/media/webcontentdecryptionmodule_impl.h
+++ b/content/renderer/media/webcontentdecryptionmodule_impl.h
@@ -23,7 +23,8 @@ class ReferenceIdAdapter;
 class WebContentDecryptionModuleImpl
     : public blink::WebContentDecryptionModule {
  public:
-  static WebContentDecryptionModuleImpl* Create(const string16& key_system);
+  static WebContentDecryptionModuleImpl* Create(
+      const base::string16& key_system);
 
   virtual ~WebContentDecryptionModuleImpl();
 
diff --git a/content/renderer/npapi/webplugin_delegate_proxy.cc b/content/renderer/npapi/webplugin_delegate_proxy.cc
index 108e292..62c4e749 100644
--- a/content/renderer/npapi/webplugin_delegate_proxy.cc
+++ b/content/renderer/npapi/webplugin_delegate_proxy.cc
@@ -749,7 +749,7 @@ NPP WebPluginDelegateProxy::GetPluginNPP() {
   return npp_.get();
 }
 
-bool WebPluginDelegateProxy::GetFormValue(string16* value) {
+bool WebPluginDelegateProxy::GetFormValue(base::string16* value) {
   bool success = false;
   Send(new PluginMsg_GetFormValue(instance_id_, value, &success));
   return success;
@@ -800,7 +800,7 @@ void WebPluginDelegateProxy::SetContentAreaFocus(bool has_focus) {
 
 #if defined(OS_WIN)
 void WebPluginDelegateProxy::ImeCompositionUpdated(
-    const string16& text,
+    const base::string16& text,
     const std::vector<int>& clauses,
     const std::vector<int>& target,
     int cursor_position,
@@ -815,7 +815,7 @@ void WebPluginDelegateProxy::ImeCompositionUpdated(
   Send(msg);
 }
 
-void WebPluginDelegateProxy::ImeCompositionCompleted(const string16& text,
+void WebPluginDelegateProxy::ImeCompositionCompleted(const base::string16& text,
                                                      int plugin_id) {
   // Dispatch the IME text if this plug-in is the focused one.
   if (instance_id_ != plugin_id)
@@ -864,7 +864,7 @@ void WebPluginDelegateProxy::WindowFrameChanged(gfx::Rect window_frame,
   msg->set_unblock(true);
   Send(msg);
 }
-void WebPluginDelegateProxy::ImeCompositionCompleted(const string16& text,
+void WebPluginDelegateProxy::ImeCompositionCompleted(const base::string16& text,
                                                      int plugin_id) {
   // If the message isn't intended for this plugin, there's nothing to do.
   if (instance_id_ != plugin_id)
@@ -1209,7 +1209,8 @@ bool WebPluginDelegateProxy::UseSynchronousGeometryUpdates() {
   // Need to update geometry synchronously with WMP, otherwise if a site
   // scripts the plugin to start playing while it's in the middle of handling
   // an update geometry message, videos don't play.  See urls in bug 20260.
-  if (info_.name.find(ASCIIToUTF16("Windows Media Player")) != string16::npos)
+  if (info_.name.find(ASCIIToUTF16("Windows Media Player")) !=
+      base::string16::npos)
     return true;
 
   // The move networks plugin needs to be informed of geometry updates
diff --git a/content/renderer/npapi/webplugin_delegate_proxy.h b/content/renderer/npapi/webplugin_delegate_proxy.h
index 679bc6d..04c4684 100644
--- a/content/renderer/npapi/webplugin_delegate_proxy.h
+++ b/content/renderer/npapi/webplugin_delegate_proxy.h
@@ -64,7 +64,7 @@ class WebPluginDelegateProxy
   virtual void Paint(SkCanvas* canvas, const gfx::Rect& rect) OVERRIDE;
   virtual NPObject* GetPluginScriptableObject() OVERRIDE;
   virtual struct _NPP* GetPluginNPP() OVERRIDE;
-  virtual bool GetFormValue(string16* value) OVERRIDE;
+  virtual bool GetFormValue(base::string16* value) OVERRIDE;
   virtual void DidFinishLoadWithReason(const GURL& url, NPReason reason,
                                        int notify_id) OVERRIDE;
   virtual void SetFocus(bool focused) OVERRIDE;
@@ -78,14 +78,15 @@ class WebPluginDelegateProxy
 #if defined(OS_WIN)
   // Informs the plugin that plugin IME has updated its status.
   virtual void ImeCompositionUpdated(
-      const string16& text,
+      const base::string16& text,
       const std::vector<int>& clauses,
       const std::vector<int>& target,
       int cursor_position,
       int plugin_id);
   // Informs the plugin that plugin IME has completed.
   // If |text| is empty, composition was cancelled.
-  virtual void ImeCompositionCompleted(const string16& text, int plugin_id);
+  virtual void ImeCompositionCompleted(const base::string16& text,
+                                       int plugin_id);
 #endif
 #if defined(OS_MACOSX)
   // Informs the plugin that its enclosing window has gained or lost focus.
@@ -96,7 +97,8 @@ class WebPluginDelegateProxy
   virtual void WindowFrameChanged(gfx::Rect window_frame, gfx::Rect view_frame);
   // Informs the plugin that plugin IME has completed.
   // If |text| is empty, composition was cancelled.
-  virtual void ImeCompositionCompleted(const string16& text, int plugin_id);
+  virtual void ImeCompositionCompleted(const base::string16& text,
+                                       int plugin_id);
 #endif
 
   // IPC::Listener implementation:
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 7e1dcaf..d187ba2 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -335,7 +335,7 @@ void RenderFrameImpl::WillHandleMouseEvent(const blink::WebMouseEvent& event) {
 }
 
 void RenderFrameImpl::SimulateImeSetComposition(
-    const string16& text,
+    const base::string16& text,
     const std::vector<blink::WebCompositionUnderline>& underlines,
     int selection_start,
     int selection_end) {
@@ -344,14 +344,14 @@ void RenderFrameImpl::SimulateImeSetComposition(
 }
 
 void RenderFrameImpl::SimulateImeConfirmComposition(
-    const string16& text,
+    const base::string16& text,
     const gfx::Range& replacement_range) {
   render_view_->OnImeConfirmComposition(text, replacement_range, false);
 }
 
 
 void RenderFrameImpl::OnImeSetComposition(
-    const string16& text,
+    const base::string16& text,
     const std::vector<blink::WebCompositionUnderline>& underlines,
     int selection_start,
     int selection_end) {
@@ -366,10 +366,10 @@ void RenderFrameImpl::OnImeSetComposition(
 
     // Empty -> nonempty: composition started.
     if (pepper_composition_text_.empty() && !text.empty())
-      focused_pepper_plugin_->HandleCompositionStart(string16());
+      focused_pepper_plugin_->HandleCompositionStart(base::string16());
     // Nonempty -> empty: composition canceled.
     if (!pepper_composition_text_.empty() && text.empty())
-      focused_pepper_plugin_->HandleCompositionEnd(string16());
+      focused_pepper_plugin_->HandleCompositionEnd(base::string16());
     pepper_composition_text_ = text;
     // Nonempty: composition is ongoing.
     if (!pepper_composition_text_.empty()) {
@@ -381,14 +381,15 @@ void RenderFrameImpl::OnImeSetComposition(
 }
 
 void RenderFrameImpl::OnImeConfirmComposition(
-    const string16& text,
+    const base::string16& text,
     const gfx::Range& replacement_range,
     bool keep_selection) {
   // When a PPAPI plugin has focus, we bypass WebKit.
   // Here, text.empty() has a special meaning. It means to commit the last
   // update of composition text (see
   // RenderWidgetHost::ImeConfirmComposition()).
-  const string16& last_text = text.empty() ? pepper_composition_text_ : text;
+  const base::string16& last_text = text.empty() ? pepper_composition_text_
+                                                 : text;
 
   // last_text is empty only when both text and pepper_composition_text_ is.
   // Ignore it.
diff --git a/content/renderer/render_frame_impl.h b/content/renderer/render_frame_impl.h
index e7a0321..bc16c75 100644
--- a/content/renderer/render_frame_impl.h
+++ b/content/renderer/render_frame_impl.h
@@ -126,22 +126,22 @@ class CONTENT_EXPORT RenderFrameImpl
 
   // Simulates IME events for testing purpose.
   void SimulateImeSetComposition(
-      const string16& text,
+      const base::string16& text,
       const std::vector<blink::WebCompositionUnderline>& underlines,
       int selection_start,
       int selection_end);
-  void SimulateImeConfirmComposition(const string16& text,
+  void SimulateImeConfirmComposition(const base::string16& text,
                                      const gfx::Range& replacement_range);
 
   // TODO(jam): remove these once the IPC handler moves from RenderView to
   // RenderFrame.
   void OnImeSetComposition(
-    const string16& text,
+    const base::string16& text,
     const std::vector<blink::WebCompositionUnderline>& underlines,
     int selection_start,
     int selection_end);
  void OnImeConfirmComposition(
-    const string16& text,
+    const base::string16& text,
     const gfx::Range& replacement_range,
     bool keep_selection);
 
@@ -325,7 +325,7 @@ class CONTENT_EXPORT RenderFrameImpl
 
   // Current text input composition text. Empty if no composition is in
   // progress.
-  string16 pepper_composition_text_;
+  base::string16 pepper_composition_text_;
 
   // The plugin instance that received the last mouse event. It is set to NULL
   // if the last mouse event went to elements other than Pepper plugins.
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 3f7ec1e..ab1545f 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -1000,7 +1000,7 @@ media::AudioHardwareConfig* RenderThreadImpl::GetAudioHardwareConfig() {
 
 #if defined(OS_WIN)
 void RenderThreadImpl::PreCacheFontCharacters(const LOGFONT& log_font,
-                                              const string16& str) {
+                                              const base::string16& str) {
   Send(new ViewHostMsg_PreCacheFontCharacters(log_font, str));
 }
 
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 1f16ee7..391911d 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -282,7 +282,8 @@ class CONTENT_EXPORT RenderThreadImpl : public RenderThread,
   media::AudioHardwareConfig* GetAudioHardwareConfig();
 
 #if defined(OS_WIN)
-  void PreCacheFontCharacters(const LOGFONT& log_font, const string16& str);
+  void PreCacheFontCharacters(const LOGFONT& log_font,
+                              const base::string16& str);
 #endif
 
 #if defined(ENABLE_WEBRTC)
diff --git a/content/renderer/render_view_browsertest.cc b/content/renderer/render_view_browsertest.cc
index a95d20b..92d8fcc 100644
--- a/content/renderer/render_view_browsertest.cc
+++ b/content/renderer/render_view_browsertest.cc
@@ -144,7 +144,7 @@ class RenderViewImplTest : public RenderViewTest {
   int SendKeyEvent(MockKeyboard::Layout layout,
                    int key_code,
                    MockKeyboard::Modifiers modifiers,
-                   string16* output) {
+                   base::string16* output) {
 #if defined(OS_WIN)
     // Retrieve the Unicode character for the given tuple (keyboard-layout,
     // key-code, and modifiers).
@@ -1052,7 +1052,7 @@ TEST_F(RenderViewImplTest, ImeComposition) {
 
       case IME_CANCELCOMPOSITION:
         view()->OnImeSetComposition(
-            string16(),
+            base::string16(),
             std::vector<blink::WebCompositionUnderline>(),
             0, 0);
         break;
@@ -1240,7 +1240,7 @@ TEST_F(RenderViewImplTest, MAYBE_OnHandleKeyboardEvent) {
         // driver is installed in a PC and the driver can assign a Unicode
         // charcter for the given tuple (key-code and modifiers).
         int key_code = kKeyCodes[k];
-        string16 char_code;
+        base::string16 char_code;
         if (SendKeyEvent(layout, key_code, modifiers, &char_code) < 0)
           continue;
 
@@ -1487,7 +1487,7 @@ TEST_F(RenderViewImplTest, MAYBE_InsertCharacters) {
         // driver is installed in a PC and the driver can assign a Unicode
         // charcter for the given tuple (layout, key-code, and modifiers).
         int key_code = kKeyCodes[k];
-        string16 char_code;
+        base::string16 char_code;
         if (SendKeyEvent(layout, key_code, modifiers, &char_code) < 0)
           continue;
       }
@@ -1745,7 +1745,7 @@ TEST_F(RenderViewImplTest, TestBackForward) {
   LoadHTML("<div id=pagename>Page A</div>");
   blink::WebHistoryItem page_a_item = GetMainFrame()->currentHistoryItem();
   int was_page_a = -1;
-  string16 check_page_a =
+  base::string16 check_page_a =
       ASCIIToUTF16(
           "Number(document.getElementById('pagename').innerHTML == 'Page A')");
   EXPECT_TRUE(ExecuteJavaScriptAndReturnIntValue(check_page_a, &was_page_a));
@@ -1753,7 +1753,7 @@ TEST_F(RenderViewImplTest, TestBackForward) {
 
   LoadHTML("<div id=pagename>Page B</div>");
   int was_page_b = -1;
-  string16 check_page_b =
+  base::string16 check_page_b =
       ASCIIToUTF16(
           "Number(document.getElementById('pagename').innerHTML == 'Page B')");
   EXPECT_TRUE(ExecuteJavaScriptAndReturnIntValue(check_page_b, &was_page_b));
@@ -1761,7 +1761,7 @@ TEST_F(RenderViewImplTest, TestBackForward) {
 
   LoadHTML("<div id=pagename>Page C</div>");
   int was_page_c = -1;
-  string16 check_page_c =
+  base::string16 check_page_c =
       ASCIIToUTF16(
           "Number(document.getElementById('pagename').innerHTML == 'Page C')");
   EXPECT_TRUE(ExecuteJavaScriptAndReturnIntValue(check_page_c, &was_page_c));
@@ -1802,14 +1802,14 @@ TEST_F(RenderViewImplTest, GetCompositionCharacterBoundsTest) {
   LoadHTML("<textarea id=\"test\"></textarea>");
   ExecuteJavaScript("document.getElementById('test').focus();");
 
-  const string16 empty_string = UTF8ToUTF16("");
+  const base::string16 empty_string = UTF8ToUTF16("");
   const std::vector<blink::WebCompositionUnderline> empty_underline;
   std::vector<gfx::Rect> bounds;
   view()->OnSetFocus(true);
   view()->OnSetInputMethodActive(true);
 
   // ASCII composition
-  const string16 ascii_composition = UTF8ToUTF16("aiueo");
+  const base::string16 ascii_composition = UTF8ToUTF16("aiueo");
   view()->OnImeSetComposition(ascii_composition, empty_underline, 0, 0);
   view()->GetCompositionCharacterBounds(&bounds);
   ASSERT_EQ(ascii_composition.size(), bounds.size());
@@ -1819,7 +1819,7 @@ TEST_F(RenderViewImplTest, GetCompositionCharacterBoundsTest) {
       empty_string, gfx::Range::InvalidRange(), false);
 
   // Non surrogate pair unicode character.
-  const string16 unicode_composition = UTF8ToUTF16(
+  const base::string16 unicode_composition = UTF8ToUTF16(
       "\xE3\x81\x82\xE3\x81\x84\xE3\x81\x86\xE3\x81\x88\xE3\x81\x8A");
   view()->OnImeSetComposition(unicode_composition, empty_underline, 0, 0);
   view()->GetCompositionCharacterBounds(&bounds);
@@ -1830,7 +1830,7 @@ TEST_F(RenderViewImplTest, GetCompositionCharacterBoundsTest) {
       empty_string, gfx::Range::InvalidRange(), false);
 
   // Surrogate pair character.
-  const string16 surrogate_pair_char = UTF8ToUTF16("\xF0\xA0\xAE\x9F");
+  const base::string16 surrogate_pair_char = UTF8ToUTF16("\xF0\xA0\xAE\x9F");
   view()->OnImeSetComposition(surrogate_pair_char,
                               empty_underline,
                               0,
@@ -1843,7 +1843,7 @@ TEST_F(RenderViewImplTest, GetCompositionCharacterBoundsTest) {
       empty_string, gfx::Range::InvalidRange(), false);
 
   // Mixed string.
-  const string16 surrogate_pair_mixed_composition =
+  const base::string16 surrogate_pair_mixed_composition =
       surrogate_pair_char + UTF8ToUTF16("\xE3\x81\x82") + surrogate_pair_char +
       UTF8ToUTF16("b") + surrogate_pair_char;
   const size_t utf16_length = 8UL;
@@ -2045,7 +2045,7 @@ class SuppressErrorPageTest : public RenderViewTest {
         const blink::WebURLError& error,
         const std::string& accept_languages,
         std::string* error_html,
-        string16* error_description) OVERRIDE {
+        base::string16* error_description) OVERRIDE {
       if (error_html)
         *error_html = "A suffusion of yellow.";
     }
diff --git a/content/renderer/render_view_browsertest_mac.mm b/content/renderer/render_view_browsertest_mac.mm
index dd1354f..f0959e0 100644
--- a/content/renderer/render_view_browsertest_mac.mm
+++ b/content/renderer/render_view_browsertest_mac.mm
@@ -86,7 +86,7 @@ TEST_F(RenderViewTest, MacTestCmdUp) {
   view->OnUpdateWebPreferences(prefs);
 
   const int kMaxOutputCharacters = 1024;
-  string16 output;
+  base::string16 output;
 
   NSEvent* arrowDownKeyDown = CmdDeadKeyEvent(NSKeyDown, kVK_DownArrow);
   NSEvent* arrowUpKeyDown = CmdDeadKeyEvent(NSKeyDown, kVK_UpArrow);
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index 9f9c7e8..42c0347 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -1103,7 +1103,7 @@ RenderViewImpl* RenderViewImpl::Create(
     int32 main_frame_routing_id,
     int32 surface_id,
     int64 session_storage_namespace_id,
-    const string16& frame_name,
+    const base::string16& frame_name,
     bool is_renderer_created,
     bool swapped_out,
     bool hidden,
@@ -1697,7 +1697,7 @@ void RenderViewImpl::OnRedo() {
                                             GetFocusedNode());
 }
 
-void RenderViewImpl::OnReplace(const string16& text) {
+void RenderViewImpl::OnReplace(const base::string16& text) {
   if (!webview())
     return;
 
@@ -1708,7 +1708,7 @@ void RenderViewImpl::OnReplace(const string16& text) {
   frame->replaceSelection(text);
 }
 
-void RenderViewImpl::OnReplaceMisspelling(const string16& text) {
+void RenderViewImpl::OnReplaceMisspelling(const base::string16& text) {
   if (!webview())
     return;
 
@@ -1781,7 +1781,7 @@ void RenderViewImpl::OnCopyToFindPboard() {
   // than the |OnCopy()| case.
   WebFrame* frame = webview()->focusedFrame();
   if (frame->hasSelection()) {
-    string16 selection = frame->selectionAsText();
+    base::string16 selection = frame->selectionAsText();
     RenderThread::Get()->Send(
         new ClipboardHostMsg_FindPboardWriteStringAsync(selection));
   }
@@ -1991,7 +1991,7 @@ void RenderViewImpl::UpdateURL(WebFrame* frame) {
       params.referrer = GetReferrerFromRequest(frame, original_request);
     }
 
-    string16 method = request.httpMethod();
+    base::string16 method = request.httpMethod();
     if (EqualsASCII(method, "POST")) {
       params.is_post = true;
       params.post_id = ExtractPostId(item);
@@ -2048,7 +2048,7 @@ void RenderViewImpl::UpdateURL(WebFrame* frame) {
 
 // Tell the embedding application that the title of the active page has changed
 void RenderViewImpl::UpdateTitle(WebFrame* frame,
-                                 const string16& title,
+                                 const base::string16& title,
                                  WebTextDirection title_direction) {
   // Ignore all but top level navigations.
   if (frame->parent())
@@ -2057,7 +2057,7 @@ void RenderViewImpl::UpdateTitle(WebFrame* frame,
   base::debug::TraceLog::GetInstance()->UpdateProcessLabel(
       routing_id_, UTF16ToUTF8(title));
 
-  string16 shortened_title = title.substr(0, kMaxTitleChars);
+  base::string16 shortened_title = title.substr(0, kMaxTitleChars);
   Send(new ViewHostMsg_UpdateTitle(routing_id_, page_id_, shortened_title,
                                    title_direction));
 }
@@ -2169,17 +2169,17 @@ void RenderViewImpl::LoadNavigationErrorPage(
 }
 
 bool RenderViewImpl::RunJavaScriptMessage(JavaScriptMessageType type,
-                                          const string16& message,
-                                          const string16& default_value,
+                                          const base::string16& message,
+                                          const base::string16& default_value,
                                           const GURL& frame_url,
-                                          string16* result) {
+                                          base::string16* result) {
   // Don't allow further dialogs if we are waiting to swap out, since the
   // PageGroupLoadDeferrer in our stack prevents it.
   if (suppress_dialogs_until_swap_out_)
     return false;
 
   bool success = false;
-  string16 result_temp;
+  base::string16 result_temp;
   if (!result)
     result = &result_temp;
 
@@ -2310,7 +2310,7 @@ WebView* RenderViewImpl::createView(
       main_frame_routing_id,
       surface_id,
       cloned_session_storage_namespace_id,
-      string16(),  // WebCore will take care of setting the correct name.
+      base::string16(),  // WebCore will take care of setting the correct name.
       true,  // is_renderer_created
       false, // swapped_out
       params.disposition == NEW_BACKGROUND_TAB, // hidden
@@ -2582,7 +2582,7 @@ void RenderViewImpl::runModalAlertDialog(WebFrame* frame,
                                          const WebString& message) {
   RunJavaScriptMessage(JAVASCRIPT_MESSAGE_TYPE_ALERT,
                        message,
-                       string16(),
+                       base::string16(),
                        frame->document().url(),
                        NULL);
 }
@@ -2591,7 +2591,7 @@ bool RenderViewImpl::runModalConfirmDialog(WebFrame* frame,
                                            const WebString& message) {
   return RunJavaScriptMessage(JAVASCRIPT_MESSAGE_TYPE_CONFIRM,
                               message,
-                              string16(),
+                              base::string16(),
                               frame->document().url(),
                               NULL);
 }
@@ -2600,7 +2600,7 @@ bool RenderViewImpl::runModalPromptDialog(WebFrame* frame,
                                           const WebString& message,
                                           const WebString& default_value,
                                           WebString* actual_value) {
-  string16 result;
+  base::string16 result;
   bool ok = RunJavaScriptMessage(JAVASCRIPT_MESSAGE_TYPE_PROMPT,
                                  message,
                                  default_value,
@@ -2636,7 +2636,7 @@ bool RenderViewImpl::runModalBeforeUnloadDialog(
   bool success = false;
   // This is an ignored return value, but is included so we can accept the same
   // response as RunJavaScriptMessage.
-  string16 ignored_result;
+  base::string16 ignored_result;
   SendAndRunNestedMessageLoop(new ViewHostMsg_RunBeforeUnloadConfirm(
       routing_id_, frame->document().url(), message, is_reload,
       &success, &ignored_result));
@@ -3806,7 +3806,7 @@ void RenderViewImpl::didFailLoad(WebFrame* frame, const WebURLError& error) {
   FOR_EACH_OBSERVER(RenderViewObserver, observers_, DidFailLoad(frame, error));
 
   const WebURLRequest& failed_request = ds->request();
-  string16 error_description;
+  base::string16 error_description;
   GetContentClient()->renderer()->GetNavigationErrorStrings(
       frame,
       failed_request,
@@ -4108,11 +4108,11 @@ void RenderViewImpl::SendFindReply(int request_id,
 
 // static
 bool RenderViewImpl::ShouldUpdateSelectionTextFromContextMenuParams(
-    const string16& selection_text,
+    const base::string16& selection_text,
     size_t selection_text_offset,
     const gfx::Range& selection_range,
     const ContextMenuParams& params) {
-  string16 trimmed_selection_text;
+  base::string16 trimmed_selection_text;
   if (!selection_text.empty() && !selection_range.is_empty()) {
     const int start = selection_range.GetMin() - selection_text_offset;
     const size_t length = selection_range.length();
@@ -4121,7 +4121,7 @@ bool RenderViewImpl::ShouldUpdateSelectionTextFromContextMenuParams(
                      &trimmed_selection_text);
     }
   }
-  string16 trimmed_params_text;
+  base::string16 trimmed_params_text;
   TrimWhitespace(params.selection_text, TRIM_ALL, &trimmed_params_text);
   return trimmed_params_text != trimmed_selection_text;
 }
@@ -4329,8 +4329,8 @@ blink::WebPlugin* RenderViewImpl::CreatePlugin(
 #endif
 }
 
-void RenderViewImpl::EvaluateScript(const string16& frame_xpath,
-                                    const string16& jscript,
+void RenderViewImpl::EvaluateScript(const base::string16& frame_xpath,
+                                    const base::string16& jscript,
                                     int id,
                                     bool notify_result) {
   v8::HandleScope handle_scope(v8::Isolate::GetCurrent());
@@ -4444,7 +4444,7 @@ void RenderViewImpl::SyncSelectionIfRequired() {
   if (!frame)
     return;
 
-  string16 text;
+  base::string16 text;
   size_t offset;
   gfx::Range range;
 #if defined(ENABLE_PLUGINS)
@@ -4572,7 +4572,7 @@ blink::WebPlugin* RenderViewImpl::GetWebPluginFromPluginDocument() {
 }
 
 void RenderViewImpl::OnFind(int request_id,
-                            const string16& search_text,
+                            const base::string16& search_text,
                             const WebFindOptions& options) {
   WebFrame* main_frame = webview()->mainFrame();
 
@@ -4858,7 +4858,7 @@ void RenderViewImpl::OnResetPageEncodingToDefault() {
   webview()->setPageEncoding(no_encoding);
 }
 
-WebFrame* RenderViewImpl::GetChildFrame(const string16& xpath) const {
+WebFrame* RenderViewImpl::GetChildFrame(const base::string16& xpath) const {
   if (xpath.empty())
     return webview()->mainFrame();
 
@@ -4867,11 +4867,11 @@ WebFrame* RenderViewImpl::GetChildFrame(const string16& xpath) const {
   // Example, /html/body/table/tbody/tr/td/iframe\n/frameset/frame[0]
   // should break into 2 xpaths
   // /html/body/table/tbody/tr/td/iframe & /frameset/frame[0]
-  std::vector<string16> xpaths;
+  std::vector<base::string16> xpaths;
   base::SplitString(xpath, '\n', &xpaths);
 
   WebFrame* frame = webview()->mainFrame();
-  for (std::vector<string16>::const_iterator i = xpaths.begin();
+  for (std::vector<base::string16>::const_iterator i = xpaths.begin();
        frame && i != xpaths.end(); ++i) {
     frame = frame->findChildByExpression(*i);
   }
@@ -4879,8 +4879,8 @@ WebFrame* RenderViewImpl::GetChildFrame(const string16& xpath) const {
   return frame;
 }
 
-void RenderViewImpl::OnScriptEvalRequest(const string16& frame_xpath,
-                                         const string16& jscript,
+void RenderViewImpl::OnScriptEvalRequest(const base::string16& frame_xpath,
+                                         const base::string16& jscript,
                                          int id,
                                          bool notify_result) {
   TRACE_EVENT_INSTANT0("test_tracing", "OnScriptEvalRequest",
@@ -4933,7 +4933,7 @@ void RenderViewImpl::OnPostMessageEvent(
   frame->dispatchMessageEventWithOriginCheck(target_origin, msg_event);
 }
 
-void RenderViewImpl::OnCSSInsertRequest(const string16& frame_xpath,
+void RenderViewImpl::OnCSSInsertRequest(const base::string16& frame_xpath,
                                         const std::string& css) {
   WebFrame* frame = GetChildFrame(frame_xpath);
   if (!frame)
@@ -5552,7 +5552,7 @@ void RenderViewImpl::OnWindowFrameChanged(const gfx::Rect& window_frame,
 #endif
 }
 
-void RenderViewImpl::OnPluginImeCompositionCompleted(const string16& text,
+void RenderViewImpl::OnPluginImeCompositionCompleted(const base::string16& text,
                                                      int plugin_id) {
   // WebPluginDelegateProxy is responsible for figuring out if this event
   // applies to it or not, so inform all the delegates.
@@ -5709,7 +5709,7 @@ void RenderViewImpl::OnSetFocus(bool enable) {
 }
 
 void RenderViewImpl::OnImeSetComposition(
-    const string16& text,
+    const base::string16& text,
     const std::vector<blink::WebCompositionUnderline>& underlines,
     int selection_start,
     int selection_end) {
@@ -5753,7 +5753,7 @@ void RenderViewImpl::OnImeSetComposition(
 }
 
 void RenderViewImpl::OnImeConfirmComposition(
-    const string16& text,
+    const base::string16& text,
     const gfx::Range& replacement_range,
     bool keep_selection) {
 #if defined(ENABLE_PLUGINS)
diff --git a/content/renderer/render_view_impl.h b/content/renderer/render_view_impl.h
index f3c7cf0..6a7ce2f 100644
--- a/content/renderer/render_view_impl.h
+++ b/content/renderer/render_view_impl.h
@@ -190,7 +190,7 @@ class CONTENT_EXPORT RenderViewImpl
       int32 main_frame_routing_id,
       int32 surface_id,
       int64 session_storage_namespace_id,
-      const string16& frame_name,
+      const base::string16& frame_name,
       bool is_renderer_created,
       bool swapped_out,
       bool hidden,
@@ -629,8 +629,8 @@ class CONTENT_EXPORT RenderViewImpl
       blink::WebFrame* frame,
       const WebPluginInfo& info,
       const blink::WebPluginParams& params) OVERRIDE;
-  virtual void EvaluateScript(const string16& frame_xpath,
-                              const string16& jscript,
+  virtual void EvaluateScript(const base::string16& frame_xpath,
+                              const base::string16& jscript,
                               int id,
                               bool notify_result) OVERRIDE;
   virtual bool ShouldDisplayScrollbars(int width, int height) const OVERRIDE;
@@ -705,11 +705,11 @@ class CONTENT_EXPORT RenderViewImpl
   virtual GURL GetURLForGraphicsContext3D() OVERRIDE;
   virtual bool ForceCompositingModeEnabled() OVERRIDE;
   virtual void OnImeSetComposition(
-      const string16& text,
+      const base::string16& text,
       const std::vector<blink::WebCompositionUnderline>& underlines,
       int selection_start,
       int selection_end) OVERRIDE;
-  virtual void OnImeConfirmComposition(const string16& text,
+  virtual void OnImeConfirmComposition(const base::string16& text,
                                        const gfx::Range& replacement_range,
                                        bool keep_selection) OVERRIDE;
   virtual void SetDeviceScaleFactor(float device_scale_factor) OVERRIDE;
@@ -819,7 +819,7 @@ class CONTENT_EXPORT RenderViewImpl
       const blink::WebURLResponse& response);
 
   void UpdateURL(blink::WebFrame* frame);
-  void UpdateTitle(blink::WebFrame* frame, const string16& title,
+  void UpdateTitle(blink::WebFrame* frame, const base::string16& title,
                    blink::WebTextDirection title_direction);
   void UpdateSessionHistory(blink::WebFrame* frame);
   void SendUpdateState(const blink::WebHistoryItem& item);
@@ -846,10 +846,10 @@ class CONTENT_EXPORT RenderViewImpl
                blink::WebNavigationPolicy policy);
 
   bool RunJavaScriptMessage(JavaScriptMessageType type,
-                            const string16& message,
-                            const string16& default_value,
+                            const base::string16& message,
+                            const base::string16& default_value,
                             const GURL& frame_url,
-                            string16* result);
+                            base::string16* result);
 
   // Sends a message and runs a nested message loop.
   bool SendAndRunNestedMessageLoop(IPC::SyncMessage* message);
@@ -870,8 +870,8 @@ class CONTENT_EXPORT RenderViewImpl
   void OnPaste();
   void OnPasteAndMatchStyle();
   void OnRedo();
-  void OnReplace(const string16& text);
-  void OnReplaceMisspelling(const string16& text);
+  void OnReplace(const base::string16& text);
+  void OnReplaceMisspelling(const base::string16& text);
   void OnScrollFocusedEditableNodeIntoRect(const gfx::Rect& rect);
   void OnSelectAll();
   void OnSelectRange(const gfx::Point& start, const gfx::Point& end);
@@ -886,7 +886,7 @@ class CONTENT_EXPORT RenderViewImpl
   void OnContextMenuClosed(const CustomContextMenuContext& custom_context);
   void OnShowContextMenu(const gfx::Point& location);
   void OnCopyImageAt(int x, int y);
-  void OnCSSInsertRequest(const string16& frame_xpath,
+  void OnCSSInsertRequest(const base::string16& frame_xpath,
                           const std::string& css);
   void OnCustomContextMenuAction(const CustomContextMenuContext& custom_context,
       unsigned action);
@@ -920,7 +920,9 @@ class CONTENT_EXPORT RenderViewImpl
   void OnExtendSelectionAndDelete(int before, int after);
   void OnFileChooserResponse(
       const std::vector<ui::SelectedFileInfo>& files);
-  void OnFind(int request_id, const string16&, const blink::WebFindOptions&);
+  void OnFind(int request_id,
+              const base::string16&,
+              const blink::WebFindOptions&);
   void OnGetAllSavableResourceLinksForCurrentPage(const GURL& page_url);
   void OnGetSerializedHtmlDataForCurrentPageWithLocalLinks(
       const std::vector<GURL>& links,
@@ -937,8 +939,8 @@ class CONTENT_EXPORT RenderViewImpl
   void OnReleaseDisambiguationPopupDIB(TransportDIB::Handle dib_handle);
   void OnReloadFrame();
   void OnResetPageEncodingToDefault();
-  void OnScriptEvalRequest(const string16& frame_xpath,
-                           const string16& jscript,
+  void OnScriptEvalRequest(const base::string16& frame_xpath,
+                           const base::string16& jscript,
                            int id,
                            bool notify_result);
   void OnSetAccessibilityMode(AccessibilityMode new_mode);
@@ -985,7 +987,8 @@ class CONTENT_EXPORT RenderViewImpl
 
 #elif defined(OS_MACOSX)
   void OnCopyToFindPboard();
-  void OnPluginImeCompositionCompleted(const string16& text, int plugin_id);
+  void OnPluginImeCompositionCompleted(const base::string16& text,
+                                       int plugin_id);
   void OnSelectPopupMenuItem(int selected_index);
   void OnSetInLiveResize(bool in_live_resize);
   void OnSetWindowVisibility(bool visible);
@@ -1031,7 +1034,7 @@ class CONTENT_EXPORT RenderViewImpl
                                 ErrorPageType error_type);
 
   // Locates a sub frame with given xpath
-  blink::WebFrame* GetChildFrame(const string16& frame_xpath) const;
+  blink::WebFrame* GetChildFrame(const base::string16& frame_xpath) const;
 
   // Returns the URL being loaded by the given frame's request.
   GURL GetLoadingUrl(blink::WebFrame* frame) const;
@@ -1089,7 +1092,7 @@ class CONTENT_EXPORT RenderViewImpl
   // Returns whether |params.selection_text| should be synchronized to the
   // browser before bringing up the context menu. Static for testing.
   static bool ShouldUpdateSelectionTextFromContextMenuParams(
-      const string16& selection_text,
+      const base::string16& selection_text,
       size_t selection_text_offset,
       const gfx::Range& selection_range,
       const ContextMenuParams& params);
@@ -1289,7 +1292,7 @@ class CONTENT_EXPORT RenderViewImpl
   // portion of this string that is the actual selected text starts at index
   // |selection_range_.GetMin() - selection_text_offset_| and has length
   // |selection_range_.length()|.
-  string16 selection_text_;
+  base::string16 selection_text_;
   // The offset corresponding to the start of |selection_text_| in the document.
   size_t selection_text_offset_;
   // Range over the document corresponding to the actual selected text (which
diff --git a/content/renderer/render_view_impl_params.cc b/content/renderer/render_view_impl_params.cc
index 253ef7f..0e77ea4 100644
--- a/content/renderer/render_view_impl_params.cc
+++ b/content/renderer/render_view_impl_params.cc
@@ -14,7 +14,7 @@ RenderViewImplParams::RenderViewImplParams(
     int32 main_frame_routing_id,
     int32 surface_id,
     int64 session_storage_namespace_id,
-    const string16& frame_name,
+    const base::string16& frame_name,
     bool is_renderer_created,
     bool swapped_out,
     bool hidden,
diff --git a/content/renderer/render_view_impl_params.h b/content/renderer/render_view_impl_params.h
index 3aec433..5993f30 100644
--- a/content/renderer/render_view_impl_params.h
+++ b/content/renderer/render_view_impl_params.h
@@ -30,7 +30,7 @@ struct CONTENT_EXPORT RenderViewImplParams {
                        int32 main_frame_routing_id,
                        int32 surface_id,
                        int64 session_storage_namespace_id,
-                       const string16& frame_name,
+                       const base::string16& frame_name,
                        bool is_renderer_created,
                        bool swapped_out,
                        bool hidden,
@@ -47,7 +47,7 @@ struct CONTENT_EXPORT RenderViewImplParams {
   int32 main_frame_routing_id;
   int32 surface_id;
   int64 session_storage_namespace_id;
-  const string16& frame_name;
+  const base::string16& frame_name;
   bool is_renderer_created;
   bool swapped_out;
   bool hidden;
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 544e4c9..17512f2 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -2105,7 +2105,7 @@ void RenderWidget::OnCandidateWindowHidden() {
 }
 
 void RenderWidget::OnImeSetComposition(
-    const string16& text,
+    const base::string16& text,
     const std::vector<WebCompositionUnderline>& underlines,
     int selection_start, int selection_end) {
   if (!ShouldHandleImeEvent())
@@ -2124,7 +2124,7 @@ void RenderWidget::OnImeSetComposition(
 #endif
 }
 
-void RenderWidget::OnImeConfirmComposition(const string16& text,
+void RenderWidget::OnImeConfirmComposition(const base::string16& text,
                                            const gfx::Range& replacement_range,
                                            bool keep_selection) {
   if (!ShouldHandleImeEvent())
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index 6129104..a9abafd 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -351,11 +351,11 @@ class CONTENT_EXPORT RenderWidget
   void OnCandidateWindowUpdated();
   void OnCandidateWindowHidden();
   virtual void OnImeSetComposition(
-      const string16& text,
+      const base::string16& text,
       const std::vector<blink::WebCompositionUnderline>& underlines,
       int selection_start,
       int selection_end);
-  virtual void OnImeConfirmComposition(const string16& text,
+  virtual void OnImeConfirmComposition(const base::string16& text,
                                        const gfx::Range& replacement_range,
                                        bool keep_selection);
   void OnPaintAtSize(const TransportDIB::Handle& dib_id,
diff --git a/content/renderer/renderer_clipboard_client.cc b/content/renderer/renderer_clipboard_client.cc
index acbc6cd..9c47463 100644
--- a/content/renderer/renderer_clipboard_client.cc
+++ b/content/renderer/renderer_clipboard_client.cc
@@ -120,15 +120,16 @@ void RendererClipboardClient::Clear(ui::ClipboardType type) {
   RenderThreadImpl::current()->Send(new ClipboardHostMsg_Clear(type));
 }
 
-void RendererClipboardClient::ReadAvailableTypes(ui::ClipboardType type,
-                                                 std::vector<string16>* types,
-                                                 bool* contains_filenames) {
+void RendererClipboardClient::ReadAvailableTypes(
+    ui::ClipboardType type,
+    std::vector<base::string16>* types,
+    bool* contains_filenames) {
   RenderThreadImpl::current()->Send(new ClipboardHostMsg_ReadAvailableTypes(
       type, types, contains_filenames));
 }
 
 void RendererClipboardClient::ReadText(ui::ClipboardType type,
-                                       string16* result) {
+                                       base::string16* result) {
   RenderThreadImpl::current()->Send(
       new ClipboardHostMsg_ReadText(type, result));
 }
@@ -140,7 +141,7 @@ void RendererClipboardClient::ReadAsciiText(ui::ClipboardType type,
 }
 
 void RendererClipboardClient::ReadHTML(ui::ClipboardType type,
-                                       string16* markup,
+                                       base::string16* markup,
                                        GURL* url, uint32* fragment_start,
                                        uint32* fragment_end) {
   RenderThreadImpl::current()->Send(new ClipboardHostMsg_ReadHTML(
@@ -166,8 +167,8 @@ void RendererClipboardClient::ReadImage(ui::ClipboardType type,
 }
 
 void RendererClipboardClient::ReadCustomData(ui::ClipboardType clipboard_type,
-                                             const string16& type,
-                                             string16* data) {
+                                             const base::string16& type,
+                                             base::string16* data) {
   RenderThreadImpl::current()->Send(
       new ClipboardHostMsg_ReadCustomData(clipboard_type, type, data));
 }
diff --git a/content/renderer/renderer_clipboard_client.h b/content/renderer/renderer_clipboard_client.h
index 1635a2b..96d05b2 100644
--- a/content/renderer/renderer_clipboard_client.h
+++ b/content/renderer/renderer_clipboard_client.h
@@ -22,22 +22,22 @@ class RendererClipboardClient : public ClipboardClient {
                                  ui::ClipboardType type) OVERRIDE;
   virtual void Clear(ui::ClipboardType type) OVERRIDE;
   virtual void ReadAvailableTypes(ui::ClipboardType type,
-                                  std::vector<string16>* types,
+                                  std::vector<base::string16>* types,
                                   bool* contains_filenames) OVERRIDE;
   virtual void ReadText(ui::ClipboardType type,
-                        string16* result) OVERRIDE;
+                        base::string16* result) OVERRIDE;
   virtual void ReadAsciiText(ui::ClipboardType type,
                              std::string* result) OVERRIDE;
   virtual void ReadHTML(ui::ClipboardType type,
-                        string16* markup,
+                        base::string16* markup,
                         GURL* url,
                         uint32* fragment_start,
                         uint32* fragment_end) OVERRIDE;
   virtual void ReadRTF(ui::ClipboardType type, std::string* result) OVERRIDE;
   virtual void ReadImage(ui::ClipboardType type, std::string* data) OVERRIDE;
   virtual void ReadCustomData(ui::ClipboardType clipboard_type,
-                              const string16& type,
-                              string16* data) OVERRIDE;
+                              const base::string16& type,
+                              base::string16* data) OVERRIDE;
   virtual void ReadData(const ui::Clipboard::FormatType& format,
                         std::string* data) OVERRIDE;
   virtual WriteContext* CreateWriteContext() OVERRIDE;
diff --git a/content/renderer/renderer_main_platform_delegate_win.cc b/content/renderer/renderer_main_platform_delegate_win.cc
index c4b4616..e425c5a 100644
--- a/content/renderer/renderer_main_platform_delegate_win.cc
+++ b/content/renderer/renderer_main_platform_delegate_win.cc
@@ -38,8 +38,9 @@ void SkiaPreCacheFontCharacters(const LOGFONT& logfont,
                                 unsigned int text_length) {
   RenderThreadImpl* render_thread_impl = RenderThreadImpl::current();
   if (render_thread_impl) {
-    render_thread_impl->PreCacheFontCharacters(logfont,
-                                               string16(text, text_length));
+    render_thread_impl->PreCacheFontCharacters(
+        logfont,
+        base::string16(text, text_length));
   }
 }
 
diff --git a/content/renderer/websharedworker_proxy.cc b/content/renderer/websharedworker_proxy.cc
index ad35f02..9b5edc5 100644
--- a/content/renderer/websharedworker_proxy.cc
+++ b/content/renderer/websharedworker_proxy.cc
@@ -51,10 +51,10 @@ void WebSharedWorkerProxy::Disconnect() {
 void WebSharedWorkerProxy::CreateWorkerContext(
     const GURL& script_url,
     bool is_shared,
-    const string16& name,
-    const string16& user_agent,
-    const string16& source_code,
-    const string16& content_security_policy,
+    const base::string16& name,
+    const base::string16& user_agent,
+    const base::string16& source_code,
+    const base::string16& content_security_policy,
     blink::WebContentSecurityPolicyType policy_type,
     int pending_route_id,
     int64 script_resource_appcache_id) {
diff --git a/content/renderer/websharedworker_proxy.h b/content/renderer/websharedworker_proxy.h
index 92f1a20..2df018a 100644
--- a/content/renderer/websharedworker_proxy.h
+++ b/content/renderer/websharedworker_proxy.h
@@ -73,10 +73,10 @@ class WebSharedWorkerProxy : public blink::WebSharedWorker,
 
   void CreateWorkerContext(const GURL& script_url,
                            bool is_shared,
-                           const string16& name,
-                           const string16& user_agent,
-                           const string16& source_code,
-                           const string16& content_security_policy,
+                           const base::string16& name,
+                           const base::string16& user_agent,
+                           const base::string16& source_code,
+                           const base::string16& content_security_policy,
                            blink::WebContentSecurityPolicyType policy_type,
                            int pending_route_id,
                            int64 script_resource_appcache_id);
diff --git a/content/shell/app/shell_breakpad_client.cc b/content/shell/app/shell_breakpad_client.cc
index c4dd86d..8e8a7d0 100644
--- a/content/shell/app/shell_breakpad_client.cc
+++ b/content/shell/app/shell_breakpad_client.cc
@@ -28,8 +28,8 @@ void ShellBreakpadClient::GetProductNameAndVersion(
     base::string16* channel_name) {
   *product_name = ASCIIToUTF16("content_shell");
   *version = ASCIIToUTF16(CONTENT_SHELL_VERSION);
-  *special_build = string16();
-  *channel_name = string16();
+  *special_build = base::string16();
+  *channel_name = base::string16();
 }
 #endif
 
diff --git a/content/shell/browser/shell.cc b/content/shell/browser/shell.cc
index f9e63e1..41b592f 100644
--- a/content/shell/browser/shell.cc
+++ b/content/shell/browser/shell.cc
@@ -323,9 +323,9 @@ JavaScriptDialogManager* Shell::GetJavaScriptDialogManager() {
 
 bool Shell::AddMessageToConsole(WebContents* source,
                                 int32 level,
-                                const string16& message,
+                                const base::string16& message,
                                 int32 line_no,
-                                const string16& source_id) {
+                                const base::string16& source_id) {
   return CommandLine::ForCurrentProcess()->HasSwitch(switches::kDumpRenderTree);
 }
 
diff --git a/content/shell/browser/shell.h b/content/shell/browser/shell.h
index 20515f6..1434b76 100644
--- a/content/shell/browser/shell.h
+++ b/content/shell/browser/shell.h
@@ -142,9 +142,9 @@ class Shell : public WebContentsDelegate,
 #endif
   virtual bool AddMessageToConsole(WebContents* source,
                                    int32 level,
-                                   const string16& message,
+                                   const base::string16& message,
                                    int32 line_no,
-                                   const string16& source_id) OVERRIDE;
+                                   const base::string16& source_id) OVERRIDE;
   virtual void RendererUnresponsive(WebContents* source) OVERRIDE;
   virtual void ActivateContents(WebContents* contents) OVERRIDE;
   virtual void DeactivateContents(WebContents* contents) OVERRIDE;
@@ -191,7 +191,7 @@ class Shell : public WebContentsDelegate,
   // Sets whether the spinner is spinning.
   void PlatformSetIsLoading(bool loading);
   // Set the title of shell window
-  void PlatformSetTitle(const string16& title);
+  void PlatformSetTitle(const base::string16& title);
 #if defined(OS_ANDROID)
   void PlatformToggleFullscreenModeForTab(WebContents* web_contents,
                                           bool enter_fullscreen);
diff --git a/content/shell/browser/shell_android.cc b/content/shell/browser/shell_android.cc
index 5cea4c1..b11ba37 100644
--- a/content/shell/browser/shell_android.cc
+++ b/content/shell/browser/shell_android.cc
@@ -60,7 +60,7 @@ void Shell::PlatformResizeSubViews() {
   // Not needed; subviews are bound.
 }
 
-void Shell::PlatformSetTitle(const string16& title) {
+void Shell::PlatformSetTitle(const base::string16& title) {
   NOTIMPLEMENTED();
 }
 
diff --git a/content/shell/browser/shell_aura.cc b/content/shell/browser/shell_aura.cc
index 6d66963..ccaffb7 100644
--- a/content/shell/browser/shell_aura.cc
+++ b/content/shell/browser/shell_aura.cc
@@ -198,7 +198,7 @@ void Shell::Close() {
   web_contents_.reset();
 }
 
-void Shell::PlatformSetTitle(const string16& title) {
+void Shell::PlatformSetTitle(const base::string16& title) {
 }
 
 }  // namespace content
diff --git a/content/shell/browser/shell_gtk.cc b/content/shell/browser/shell_gtk.cc
index 66d17ce7..3d2580a 100644
--- a/content/shell/browser/shell_gtk.cc
+++ b/content/shell/browser/shell_gtk.cc
@@ -335,7 +335,7 @@ gboolean Shell::OnReloadKeyPressed(GtkAccelGroup* accel_group,
   return TRUE;
 }
 
-void Shell::PlatformSetTitle(const string16& title) {
+void Shell::PlatformSetTitle(const base::string16& title) {
   if (headless_)
     return;
 
diff --git a/content/shell/browser/shell_javascript_dialog.h b/content/shell/browser/shell_javascript_dialog.h
index 4001334..233296b 100644
--- a/content/shell/browser/shell_javascript_dialog.h
+++ b/content/shell/browser/shell_javascript_dialog.h
@@ -29,8 +29,8 @@ class ShellJavaScriptDialog {
       ShellJavaScriptDialogManager* manager,
       gfx::NativeWindow parent_window,
       JavaScriptMessageType message_type,
-      const string16& message_text,
-      const string16& default_prompt_text,
+      const base::string16& message_text,
+      const base::string16& default_prompt_text,
       const JavaScriptDialogManager::DialogClosedCallback& callback);
   ~ShellJavaScriptDialog();
 
@@ -46,8 +46,8 @@ class ShellJavaScriptDialog {
 #elif defined(OS_WIN)
   JavaScriptMessageType message_type_;
   HWND dialog_win_;
-  string16 message_text_;
-  string16 default_prompt_text_;
+  base::string16 message_text_;
+  base::string16 default_prompt_text_;
   static INT_PTR CALLBACK DialogProc(HWND dialog, UINT message, WPARAM wparam,
                                      LPARAM lparam);
 #elif defined(TOOLKIT_GTK)
diff --git a/content/shell/browser/shell_javascript_dialog_gtk.cc b/content/shell/browser/shell_javascript_dialog_gtk.cc
index 87bd6f3..65bf739 100644
--- a/content/shell/browser/shell_javascript_dialog_gtk.cc
+++ b/content/shell/browser/shell_javascript_dialog_gtk.cc
@@ -19,12 +19,12 @@ const char kPromptTextId[] = "content_shell_prompt_text";
 
 // If there's a text entry in the dialog, get the text from the first one and
 // return it.
-string16 GetPromptText(GtkDialog* dialog) {
+base::string16 GetPromptText(GtkDialog* dialog) {
   GtkWidget* widget = static_cast<GtkWidget*>(
       g_object_get_data(G_OBJECT(dialog), kPromptTextId));
   if (widget)
     return UTF8ToUTF16(gtk_entry_get_text(GTK_ENTRY(widget)));
-  return string16();
+  return base::string16();
 }
 
 }  // namespace
@@ -36,8 +36,8 @@ ShellJavaScriptDialog::ShellJavaScriptDialog(
     ShellJavaScriptDialogManager* manager,
     gfx::NativeWindow parent_window,
     JavaScriptMessageType message_type,
-    const string16& message_text,
-    const string16& default_prompt_text,
+    const base::string16& message_text,
+    const base::string16& default_prompt_text,
     const JavaScriptDialogManager::DialogClosedCallback& callback)
     : manager_(manager),
       callback_(callback),
@@ -113,7 +113,7 @@ void ShellJavaScriptDialog::OnResponse(GtkWidget* dialog, int response_id) {
       break;
     case GTK_RESPONSE_CANCEL:
     case GTK_RESPONSE_DELETE_EVENT:
-      callback_.Run(false, string16());
+      callback_.Run(false, base::string16());
       break;
     default:
       NOTREACHED();
diff --git a/content/shell/browser/shell_javascript_dialog_mac.mm b/content/shell/browser/shell_javascript_dialog_mac.mm
index fe9de98..e748000 100644
--- a/content/shell/browser/shell_javascript_dialog_mac.mm
+++ b/content/shell/browser/shell_javascript_dialog_mac.mm
@@ -66,7 +66,7 @@
     return;
 
   bool success = returnCode == NSAlertFirstButtonReturn;
-  string16 input;
+  base::string16 input;
   if (textField_)
     input = base::SysNSStringToUTF16([textField_ stringValue]);
 
@@ -89,8 +89,8 @@ ShellJavaScriptDialog::ShellJavaScriptDialog(
     ShellJavaScriptDialogManager* manager,
     gfx::NativeWindow parent_window,
     JavaScriptMessageType message_type,
-    const string16& message_text,
-    const string16& default_prompt_text,
+    const base::string16& message_text,
+    const base::string16& default_prompt_text,
     const JavaScriptDialogManager::DialogClosedCallback& callback)
     : manager_(manager),
       callback_(callback) {
diff --git a/content/shell/browser/shell_javascript_dialog_manager.cc b/content/shell/browser/shell_javascript_dialog_manager.cc
index 1476f7c..6ac7243b 100644
--- a/content/shell/browser/shell_javascript_dialog_manager.cc
+++ b/content/shell/browser/shell_javascript_dialog_manager.cc
@@ -27,18 +27,18 @@ void ShellJavaScriptDialogManager::RunJavaScriptDialog(
     const GURL& origin_url,
     const std::string& accept_lang,
     JavaScriptMessageType javascript_message_type,
-    const string16& message_text,
-    const string16& default_prompt_text,
+    const base::string16& message_text,
+    const base::string16& default_prompt_text,
     const DialogClosedCallback& callback,
     bool* did_suppress_message) {
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kDumpRenderTree)) {
-    callback.Run(true, string16());
+    callback.Run(true, base::string16());
     return;
   }
 
   if (!dialog_request_callback_.is_null()) {
     dialog_request_callback_.Run();
-    callback.Run(true, string16());
+    callback.Run(true, base::string16());
     dialog_request_callback_.Reset();
     return;
   }
@@ -52,7 +52,7 @@ void ShellJavaScriptDialogManager::RunJavaScriptDialog(
     return;
   }
 
-  string16 new_message_text = net::FormatUrl(origin_url, accept_lang) +
+  base::string16 new_message_text = net::FormatUrl(origin_url, accept_lang) +
                               ASCIIToUTF16("\n\n") +
                               message_text;
   gfx::NativeWindow parent_window =
@@ -73,17 +73,17 @@ void ShellJavaScriptDialogManager::RunJavaScriptDialog(
 
 void ShellJavaScriptDialogManager::RunBeforeUnloadDialog(
     WebContents* web_contents,
-    const string16& message_text,
+    const base::string16& message_text,
     bool is_reload,
     const DialogClosedCallback& callback) {
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kDumpRenderTree)) {
-    callback.Run(true, string16());
+    callback.Run(true, base::string16());
     return;
   }
 
   if (!dialog_request_callback_.is_null()) {
     dialog_request_callback_.Run();
-    callback.Run(true, string16());
+    callback.Run(true, base::string16());
     dialog_request_callback_.Reset();
     return;
   }
@@ -91,11 +91,11 @@ void ShellJavaScriptDialogManager::RunBeforeUnloadDialog(
 #if defined(OS_MACOSX) || defined(OS_WIN) || defined(TOOLKIT_GTK)
   if (dialog_) {
     // Seriously!?
-    callback.Run(true, string16());
+    callback.Run(true, base::string16());
     return;
   }
 
-  string16 new_message_text =
+  base::string16 new_message_text =
       message_text +
       ASCIIToUTF16("\n\nIs it OK to leave/reload this page?");
 
@@ -106,11 +106,11 @@ void ShellJavaScriptDialogManager::RunBeforeUnloadDialog(
                                           parent_window,
                                           JAVASCRIPT_MESSAGE_TYPE_CONFIRM,
                                           new_message_text,
-                                          string16(),  // default_prompt_text
+                                          base::string16(),  // default
                                           callback));
 #else
   // TODO: implement ShellJavaScriptDialog for other platforms, drop this #if
-  callback.Run(true, string16());
+  callback.Run(true, base::string16());
   return;
 #endif
 }
diff --git a/content/shell/browser/shell_javascript_dialog_manager.h b/content/shell/browser/shell_javascript_dialog_manager.h
index 763736f..5bcfb65 100644
--- a/content/shell/browser/shell_javascript_dialog_manager.h
+++ b/content/shell/browser/shell_javascript_dialog_manager.h
@@ -25,14 +25,14 @@ class ShellJavaScriptDialogManager : public JavaScriptDialogManager {
       const GURL& origin_url,
       const std::string& accept_lang,
       JavaScriptMessageType javascript_message_type,
-      const string16& message_text,
-      const string16& default_prompt_text,
+      const base::string16& message_text,
+      const base::string16& default_prompt_text,
       const DialogClosedCallback& callback,
       bool* did_suppress_message) OVERRIDE;
 
   virtual void RunBeforeUnloadDialog(
       WebContents* web_contents,
-      const string16& message_text,
+      const base::string16& message_text,
       bool is_reload,
       const DialogClosedCallback& callback) OVERRIDE;
 
diff --git a/content/shell/browser/shell_javascript_dialog_win.cc b/content/shell/browser/shell_javascript_dialog_win.cc
index a59639e..3537122 100644
--- a/content/shell/browser/shell_javascript_dialog_win.cc
+++ b/content/shell/browser/shell_javascript_dialog_win.cc
@@ -34,7 +34,7 @@ INT_PTR CALLBACK ShellJavaScriptDialog::DialogProc(HWND dialog,
           GetWindowLongPtr(dialog, DWLP_USER));
       if (owner->dialog_win_) {
         owner->dialog_win_ = 0;
-        owner->callback_.Run(false, string16());
+        owner->callback_.Run(false, base::string16());
         owner->manager_->DialogClosed(owner);
       }
       break;
@@ -42,7 +42,7 @@ INT_PTR CALLBACK ShellJavaScriptDialog::DialogProc(HWND dialog,
     case WM_COMMAND: {
       ShellJavaScriptDialog* owner = reinterpret_cast<ShellJavaScriptDialog*>(
           GetWindowLongPtr(dialog, DWLP_USER));
-      string16 user_input;
+      base::string16 user_input;
       bool finish = false;
       bool result;
       switch (LOWORD(wparam)) {
@@ -79,8 +79,8 @@ ShellJavaScriptDialog::ShellJavaScriptDialog(
     ShellJavaScriptDialogManager* manager,
     gfx::NativeWindow parent_window,
     JavaScriptMessageType message_type,
-    const string16& message_text,
-    const string16& default_prompt_text,
+    const base::string16& message_text,
+    const base::string16& default_prompt_text,
     const JavaScriptDialogManager::DialogClosedCallback& callback)
     : manager_(manager),
       callback_(callback),
diff --git a/content/shell/browser/shell_login_dialog.cc b/content/shell/browser/shell_login_dialog.cc
index 607fd66..b01fe98 100644
--- a/content/shell/browser/shell_login_dialog.cc
+++ b/content/shell/browser/shell_login_dialog.cc
@@ -34,8 +34,8 @@ void ShellLoginDialog::OnRequestCancelled() {
       base::Bind(&ShellLoginDialog::PlatformRequestCancelled, this));
 }
 
-void ShellLoginDialog::UserAcceptedAuth(const string16& username,
-                                        const string16& password) {
+void ShellLoginDialog::UserAcceptedAuth(const base::string16& username,
+                                        const base::string16& password) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
@@ -48,7 +48,7 @@ void ShellLoginDialog::UserCancelledAuth() {
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&ShellLoginDialog::SendAuthToRequester, this,
-                 false, string16(), string16()));
+                 false, base::string16(), base::string16()));
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&ShellLoginDialog::PlatformCleanUp, this));
@@ -63,20 +63,20 @@ ShellLoginDialog::~ShellLoginDialog() {
 // Bogus implementations for linking. They are never called because
 // ResourceDispatcherHostDelegate::CreateLoginDelegate returns NULL.
 // TODO: implement ShellLoginDialog for other platforms, drop this #if
-void ShellLoginDialog::PlatformCreateDialog(const string16& message) {}
+void ShellLoginDialog::PlatformCreateDialog(const base::string16& message) {}
 void ShellLoginDialog::PlatformCleanUp() {}
 void ShellLoginDialog::PlatformRequestCancelled() {}
 #endif
 
-void ShellLoginDialog::PrepDialog(const string16& host,
-                                  const string16& realm) {
+void ShellLoginDialog::PrepDialog(const base::string16& host,
+                                  const base::string16& realm) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // The realm is controlled by the remote server, so there is no reason to
   // believe it is of a reasonable length.
-  string16 elided_realm;
+  base::string16 elided_realm;
   gfx::ElideString(realm, 120, &elided_realm);
 
-  string16 explanation =
+  base::string16 explanation =
       ASCIIToUTF16("The server ") + host +
       ASCIIToUTF16(" requires a username and password.");
 
@@ -90,8 +90,8 @@ void ShellLoginDialog::PrepDialog(const string16& host,
 }
 
 void ShellLoginDialog::SendAuthToRequester(bool success,
-                                           const string16& username,
-                                           const string16& password) {
+                                           const base::string16& username,
+                                           const base::string16& password) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   if (success)
     request_->SetAuth(net::AuthCredentials(username, password));
diff --git a/content/shell/browser/shell_login_dialog.h b/content/shell/browser/shell_login_dialog.h
index d9b0504..db70cb6 100644
--- a/content/shell/browser/shell_login_dialog.h
+++ b/content/shell/browser/shell_login_dialog.h
@@ -43,7 +43,8 @@ class ShellLoginDialog : public ResourceDispatcherHostLoginDelegate {
   // the aforementioned platform specific code may not have access to private
   // members. Not to be called from client code.
   // Threading: UI thread.
-  void UserAcceptedAuth(const string16& username, const string16& password);
+  void UserAcceptedAuth(const base::string16& username,
+                        const base::string16& password);
   void UserCancelledAuth();
 
  protected:
@@ -55,7 +56,7 @@ class ShellLoginDialog : public ResourceDispatcherHostLoginDelegate {
   // platform specific LoginDialog implementation.
   // Creates the dialog.
   // Threading: UI thread.
-  void PlatformCreateDialog(const string16& message);
+  void PlatformCreateDialog(const base::string16& message);
   // Called from the destructor to let each platform do any necessary cleanup.
   // Threading: UI thread.
   void PlatformCleanUp();
@@ -65,13 +66,13 @@ class ShellLoginDialog : public ResourceDispatcherHostLoginDelegate {
 
   // Sets up dialog creation.
   // Threading: UI thread.
-  void PrepDialog(const string16& host, const string16& realm);
+  void PrepDialog(const base::string16& host, const base::string16& realm);
 
   // Sends the authentication to the requester.
   // Threading: IO thread.
   void SendAuthToRequester(bool success,
-                           const string16& username,
-                           const string16& password);
+                           const base::string16& username,
+                           const base::string16& password);
 
   // Who/where/what asked for the authentication.
   // Threading: IO thread.
diff --git a/content/shell/browser/shell_login_dialog_gtk.cc b/content/shell/browser/shell_login_dialog_gtk.cc
index b08b449..97fafec 100644
--- a/content/shell/browser/shell_login_dialog_gtk.cc
+++ b/content/shell/browser/shell_login_dialog_gtk.cc
@@ -19,7 +19,7 @@
 
 namespace content {
 
-void ShellLoginDialog::PlatformCreateDialog(const string16& message) {
+void ShellLoginDialog::PlatformCreateDialog(const base::string16& message) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   int render_process_id;
diff --git a/content/shell/browser/shell_login_dialog_mac.mm b/content/shell/browser/shell_login_dialog_mac.mm
index 447aa58..3e014e8 100644
--- a/content/shell/browser/shell_login_dialog_mac.mm
+++ b/content/shell/browser/shell_login_dialog_mac.mm
@@ -87,7 +87,7 @@ const int kPasswordFieldTag = 2;
 
 namespace content {
 
-void ShellLoginDialog::PlatformCreateDialog(const string16& message) {
+void ShellLoginDialog::PlatformCreateDialog(const base::string16& message) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   helper_ = [[ShellLoginDialogHelper alloc] init];
 
diff --git a/content/shell/browser/shell_mac.mm b/content/shell/browser/shell_mac.mm
index 335f4af..e31ba09 100644
--- a/content/shell/browser/shell_mac.mm
+++ b/content/shell/browser/shell_mac.mm
@@ -274,7 +274,7 @@ void Shell::PlatformResizeSubViews() {
   // Not needed; subviews are bound.
 }
 
-void Shell::PlatformSetTitle(const string16& title) {
+void Shell::PlatformSetTitle(const base::string16& title) {
   if (headless_)
     return;
 
diff --git a/content/shell/browser/shell_network_delegate.cc b/content/shell/browser/shell_network_delegate.cc
index 560426f..1e4dddc 100644
--- a/content/shell/browser/shell_network_delegate.cc
+++ b/content/shell/browser/shell_network_delegate.cc
@@ -69,7 +69,7 @@ void ShellNetworkDelegate::OnURLRequestDestroyed(net::URLRequest* request) {
 }
 
 void ShellNetworkDelegate::OnPACScriptError(int line_number,
-                                            const string16& error) {
+                                            const base::string16& error) {
 }
 
 ShellNetworkDelegate::AuthRequiredResponse ShellNetworkDelegate::OnAuthRequired(
diff --git a/content/shell/browser/shell_network_delegate.h b/content/shell/browser/shell_network_delegate.h
index a3ce0a2..286cc0a 100644
--- a/content/shell/browser/shell_network_delegate.h
+++ b/content/shell/browser/shell_network_delegate.h
@@ -42,7 +42,7 @@ class ShellNetworkDelegate : public net::NetworkDelegate {
   virtual void OnCompleted(net::URLRequest* request, bool started) OVERRIDE;
   virtual void OnURLRequestDestroyed(net::URLRequest* request) OVERRIDE;
   virtual void OnPACScriptError(int line_number,
-                                const string16& error) OVERRIDE;
+                                const base::string16& error) OVERRIDE;
   virtual AuthRequiredResponse OnAuthRequired(
       net::URLRequest* request,
       const net::AuthChallengeInfo& auth_info,
diff --git a/content/shell/browser/shell_views.cc b/content/shell/browser/shell_views.cc
index 273eef6..e137fcb 100644
--- a/content/shell/browser/shell_views.cc
+++ b/content/shell/browser/shell_views.cc
@@ -110,7 +110,7 @@ class ShellWindowDelegateView : public views::WidgetDelegateView,
 #endif
   }
 
-  void SetWindowTitle(const string16& title) { title_ = title; }
+  void SetWindowTitle(const base::string16& title) { title_ = title; }
   void EnableUIControl(UIControl control, bool is_enabled) {
     if (control == BACK_BUTTON) {
       back_button_->SetState(is_enabled ? views::CustomButton::STATE_NORMAL
@@ -215,7 +215,7 @@ class ShellWindowDelegateView : public views::WidgetDelegateView,
   }
   // Overridden from TextfieldController
   virtual void ContentsChanged(views::Textfield* sender,
-                               const string16& new_contents) OVERRIDE {
+                               const base::string16& new_contents) OVERRIDE {
   }
   virtual bool HandleKeyEvent(views::Textfield* sender,
                               const ui::KeyEvent& key_event) OVERRIDE {
@@ -248,7 +248,7 @@ class ShellWindowDelegateView : public views::WidgetDelegateView,
   // Overridden from WidgetDelegateView
   virtual bool CanResize() const OVERRIDE { return true; }
   virtual bool CanMaximize() const OVERRIDE { return true; }
-  virtual string16 GetWindowTitle() const OVERRIDE {
+  virtual base::string16 GetWindowTitle() const OVERRIDE {
     return title_;
   }
   virtual void WindowClosing() OVERRIDE {
@@ -272,7 +272,7 @@ class ShellWindowDelegateView : public views::WidgetDelegateView,
   Shell* shell_;
 
   // Window title
-  string16 title_;
+  base::string16 title_;
 
   // Toolbar view contains forward/backward/reload button and URL entry
   View* toolbar_view_;
@@ -387,7 +387,7 @@ void Shell::Close() {
   window_widget_->CloseNow();
 }
 
-void Shell::PlatformSetTitle(const string16& title) {
+void Shell::PlatformSetTitle(const base::string16& title) {
   ShellWindowDelegateView* delegate_view =
     static_cast<ShellWindowDelegateView*>(window_widget_->widget_delegate());
   delegate_view->SetWindowTitle(title);
diff --git a/content/shell/browser/shell_win.cc b/content/shell/browser/shell_win.cc
index 0cd65db..b9e57a9 100644
--- a/content/shell/browser/shell_win.cc
+++ b/content/shell/browser/shell_win.cc
@@ -278,7 +278,7 @@ LRESULT CALLBACK Shell::EditWndProc(HWND hwnd, UINT message,
                         lParam);
 }
 
-void Shell::PlatformSetTitle(const string16& text) {
+void Shell::PlatformSetTitle(const base::string16& text) {
   ::SetWindowText(window_, text.c_str());
 }
 
diff --git a/content/shell/common/shell_content_client.cc b/content/shell/common/shell_content_client.cc
index 495ad85..8cb0f88 100644
--- a/content/shell/common/shell_content_client.cc
+++ b/content/shell/common/shell_content_client.cc
@@ -29,7 +29,7 @@ std::string ShellContentClient::GetUserAgent() const {
   return webkit_glue::BuildUserAgentFromProduct(product);
 }
 
-string16 ShellContentClient::GetLocalizedString(int message_id) const {
+base::string16 ShellContentClient::GetLocalizedString(int message_id) const {
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kDumpRenderTree)) {
     switch (message_id) {
       case IDS_FORM_OTHER_DATE_LABEL:
diff --git a/content/shell/common/shell_content_client.h b/content/shell/common/shell_content_client.h
index 84a1483..478c065 100644
--- a/content/shell/common/shell_content_client.h
+++ b/content/shell/common/shell_content_client.h
@@ -18,7 +18,7 @@ class ShellContentClient : public ContentClient {
   virtual ~ShellContentClient();
 
   virtual std::string GetUserAgent() const OVERRIDE;
-  virtual string16 GetLocalizedString(int message_id) const OVERRIDE;
+  virtual base::string16 GetLocalizedString(int message_id) const OVERRIDE;
   virtual base::StringPiece GetDataResource(
       int resource_id,
       ui::ScaleFactor scale_factor) const OVERRIDE;
diff --git a/content/shell/common/webkit_test_helpers.cc b/content/shell/common/webkit_test_helpers.cc
index a0cebeb..3d3212e 100644
--- a/content/shell/common/webkit_test_helpers.cc
+++ b/content/shell/common/webkit_test_helpers.cc
@@ -71,7 +71,7 @@ void ApplyLayoutTestDefaultPreferences(WebPreferences* prefs) {
   prefs->allow_displaying_insecure_content = true;
   prefs->allow_running_insecure_content = true;
   prefs->webgl_errors_to_console_enabled = false;
-  string16 serif;
+  base::string16 serif;
 #if defined(OS_MACOSX)
   prefs->cursive_font_family_map[webkit_glue::kCommonScript] =
       ASCIIToUTF16("Apple Chancery");
diff --git a/content/shell/geolocation/shell_access_token_store.cc b/content/shell/geolocation/shell_access_token_store.cc
index ceae3d6..4b8b007 100644
--- a/content/shell/geolocation/shell_access_token_store.cc
+++ b/content/shell/geolocation/shell_access_token_store.cc
@@ -49,7 +49,7 @@ void ShellAccessTokenStore::RespondOnOriginatingThread(
 }
 
 void ShellAccessTokenStore::SaveAccessToken(
-    const GURL& server_url, const string16& access_token) {
+    const GURL& server_url, const base::string16& access_token) {
 }
 
 }  // namespace content
diff --git a/content/shell/geolocation/shell_access_token_store.h b/content/shell/geolocation/shell_access_token_store.h
index 82ee0f8..0345b8c 100644
--- a/content/shell/geolocation/shell_access_token_store.h
+++ b/content/shell/geolocation/shell_access_token_store.h
@@ -28,7 +28,7 @@ class ShellAccessTokenStore : public content::AccessTokenStore {
       const LoadAccessTokensCallbackType& callback) OVERRIDE;
 
   virtual void SaveAccessToken(
-      const GURL& server_url, const string16& access_token) OVERRIDE;
+      const GURL& server_url, const base::string16& access_token) OVERRIDE;
 
   content::ShellBrowserContext* shell_browser_context_;
   net::URLRequestContextGetter* system_request_context_;
diff --git a/content/test/content_browser_test_test.cc b/content/test/content_browser_test_test.cc
index 8738a00..b9bf217 100644
--- a/content/test/content_browser_test_test.cc
+++ b/content/test/content_browser_test_test.cc
@@ -31,10 +31,10 @@ class ContentBrowserTestSanityTest : public ContentBrowserTest {
   void Test() {
     GURL url = GetTestUrl(".", "simple_page.html");
 
-    string16 expected_title(ASCIIToUTF16("OK"));
+    base::string16 expected_title(ASCIIToUTF16("OK"));
     TitleWatcher title_watcher(shell()->web_contents(), expected_title);
     NavigateToURL(shell(), url);
-    string16 title = title_watcher.WaitAndGetTitle();
+    base::string16 title = title_watcher.WaitAndGetTitle();
     EXPECT_EQ(expected_title, title);
   }
 };
diff --git a/content/test/test_web_contents.cc b/content/test/test_web_contents.cc
index 4a4ad04..33332bd 100644
--- a/content/test/test_web_contents.cc
+++ b/content/test/test_web_contents.cc
@@ -94,7 +94,7 @@ bool TestWebContents::CreateRenderViewForRenderManager(
     RenderViewHost* render_view_host, int opener_route_id) {
   // This will go to a TestRenderViewHost.
   static_cast<RenderViewHostImpl*>(
-      render_view_host)->CreateRenderView(string16(),
+      render_view_host)->CreateRenderView(base::string16(),
                                           opener_route_id,
                                           -1);
   return true;
@@ -212,7 +212,7 @@ void TestWebContents::TestDidFailLoadWithError(
     const GURL& url,
     bool is_main_frame,
     int error_code,
-    const string16& error_description) {
+    const base::string16& error_description) {
   ViewHostMsg_DidFailLoadWithError msg(
       0, frame_id, url, is_main_frame, error_code, error_description);
   OnMessageReceived(GetRenderViewHost(), msg);
diff --git a/content/test/test_web_contents.h b/content/test/test_web_contents.h
index 7b308d8..5f338c6 100644
--- a/content/test/test_web_contents.h
+++ b/content/test/test_web_contents.h
@@ -97,7 +97,7 @@ class TestWebContents : public WebContentsImpl, public WebContentsTester {
                                 const GURL& url,
                                 bool is_main_frame,
                                 int error_code,
-                                const string16& error_description);
+                                const base::string16& error_description);
 
  protected:
   // The deprecated WebContentsTester still needs to subclass this.
diff --git a/content/test/test_web_contents_view.cc b/content/test/test_web_contents_view.cc
index 9bed145..793a77c 100644
--- a/content/test/test_web_contents_view.cc
+++ b/content/test/test_web_contents_view.cc
@@ -103,7 +103,7 @@ RenderWidgetHostView* TestWebContentsView::CreateViewForPopupWidget(
   return NULL;
 }
 
-void TestWebContentsView::SetPageTitle(const string16& title) {
+void TestWebContentsView::SetPageTitle(const base::string16& title) {
 }
 
 void TestWebContentsView::RenderViewCreated(RenderViewHost* host) {
diff --git a/content/test/test_web_contents_view.h b/content/test/test_web_contents_view.h
index 707b632..045f092 100644
--- a/content/test/test_web_contents_view.h
+++ b/content/test/test_web_contents_view.h
@@ -60,7 +60,7 @@ class TestWebContentsView : public WebContentsViewPort,
       RenderWidgetHost* render_widget_host) OVERRIDE;
   virtual RenderWidgetHostView* CreateViewForPopupWidget(
       RenderWidgetHost* render_widget_host) OVERRIDE;
-  virtual void SetPageTitle(const string16& title) OVERRIDE;
+  virtual void SetPageTitle(const base::string16& title) OVERRIDE;
   virtual void RenderViewCreated(RenderViewHost* host) OVERRIDE;
   virtual void RenderViewSwappedIn(RenderViewHost* host) OVERRIDE;
   virtual void SetOverscrollControllerEnabled(bool enabled) OVERRIDE;
diff --git a/content/test/weburl_loader_mock_factory.cc b/content/test/weburl_loader_mock_factory.cc
index 2c91e6f..791ae1e 100644
--- a/content/test/weburl_loader_mock_factory.cc
+++ b/content/test/weburl_loader_mock_factory.cc
@@ -39,7 +39,7 @@ void WebURLLoaderMockFactory::RegisterURL(const WebURL& url,
     response_info.file_path =
         base::FilePath(static_cast<std::string>(file_path.utf8()));
 #elif defined(OS_WIN)
-    string16 file_path_16 = file_path;
+    base::string16 file_path_16 = file_path;
     response_info.file_path = base::FilePath(std::wstring(
         file_path_16.data(), file_path_16.length()));
 #endif
diff --git a/content/worker/websharedworker_stub.cc b/content/worker/websharedworker_stub.cc
index 2a551f3..d77db25 100644
--- a/content/worker/websharedworker_stub.cc
+++ b/content/worker/websharedworker_stub.cc
@@ -19,7 +19,7 @@
 namespace content {
 
 WebSharedWorkerStub::WebSharedWorkerStub(
-    const string16& name,
+    const base::string16& name,
     int route_id,
     const WorkerAppCacheInitInfo& appcache_init_info)
     : route_id_(route_id),
@@ -81,8 +81,9 @@ const GURL& WebSharedWorkerStub::url() {
 }
 
 void WebSharedWorkerStub::OnStartWorkerContext(
-    const GURL& url, const string16& user_agent, const string16& source_code,
-    const string16& content_security_policy,
+    const GURL& url, const base::string16& user_agent,
+    const base::string16& source_code,
+    const base::string16& content_security_policy,
     blink::WebContentSecurityPolicyType policy_type) {
   // Ignore multiple attempts to start this worker (can happen if two pages
   // try to start it simultaneously).
diff --git a/content/worker/websharedworker_stub.h b/content/worker/websharedworker_stub.h
index ee5f509..66d11ea 100644
--- a/content/worker/websharedworker_stub.h
+++ b/content/worker/websharedworker_stub.h
@@ -25,7 +25,7 @@ class SharedWorkerDevToolsAgent;
 // appropriate WebSharedWorker APIs.
 class WebSharedWorkerStub : public IPC::Listener {
  public:
-  WebSharedWorkerStub(const string16& name, int route_id,
+  WebSharedWorkerStub(const base::string16& name, int route_id,
                       const WorkerAppCacheInitInfo& appcache_init_info);
 
   // IPC::Listener implementation.
@@ -54,8 +54,9 @@ class WebSharedWorkerStub : public IPC::Listener {
 
   void OnConnect(int sent_message_port_id, int routing_id);
   void OnStartWorkerContext(
-      const GURL& url, const string16& user_agent, const string16& source_code,
-      const string16& content_security_policy,
+      const GURL& url, const base::string16& user_agent,
+      const base::string16& source_code,
+      const base::string16& content_security_policy,
       blink::WebContentSecurityPolicyType policy_type);
 
   void OnTerminateWorkerContext();
@@ -70,7 +71,7 @@ class WebSharedWorkerStub : public IPC::Listener {
   WebSharedWorkerClientProxy client_;
 
   blink::WebSharedWorker* impl_;
-  string16 name_;
+  base::string16 name_;
   bool started_;
   GURL url_;
   scoped_ptr<SharedWorkerDevToolsAgent> worker_devtools_agent_;
diff --git a/google_apis/gaia/oauth2_mint_token_flow.cc b/google_apis/gaia/oauth2_mint_token_flow.cc
index b3641eb..a1e3ff3 100644
--- a/google_apis/gaia/oauth2_mint_token_flow.cc
+++ b/google_apis/gaia/oauth2_mint_token_flow.cc
@@ -258,7 +258,7 @@ bool OAuth2MintTokenFlow::ParseIssueAdviceResponse(
   for (size_t index = 0; index < scopes_list->GetSize(); ++index) {
     const base::DictionaryValue* scopes_entry = NULL;
     IssueAdviceInfoEntry entry;
-    string16 detail;
+    base::string16 detail;
     if (!scopes_list->GetDictionary(index, &scopes_entry) ||
         !scopes_entry->GetString(kDescriptionKey, &entry.description) ||
         !scopes_entry->GetString(kDetailKey, &detail)) {
@@ -267,7 +267,8 @@ bool OAuth2MintTokenFlow::ParseIssueAdviceResponse(
     }
 
     TrimWhitespace(entry.description, TRIM_ALL, &entry.description);
-    static const string16 detail_separators = ASCIIToUTF16(kDetailSeparators);
+    static const base::string16 detail_separators =
+        ASCIIToUTF16(kDetailSeparators);
     Tokenize(detail, detail_separators, &entry.details);
     for (size_t i = 0; i < entry.details.size(); i++)
       TrimWhitespace(entry.details[i], TRIM_ALL, &entry.details[i]);
diff --git a/google_apis/gaia/oauth2_mint_token_flow.h b/google_apis/gaia/oauth2_mint_token_flow.h
index 5bb751d..06c823c 100644
--- a/google_apis/gaia/oauth2_mint_token_flow.h
+++ b/google_apis/gaia/oauth2_mint_token_flow.h
@@ -43,8 +43,8 @@ struct IssueAdviceInfoEntry {
   IssueAdviceInfoEntry();
   ~IssueAdviceInfoEntry();
 
-  string16 description;
-  std::vector<string16> details;
+  base::string16 description;
+  std::vector<base::string16> details;
 
   bool operator==(const IssueAdviceInfoEntry& rhs) const;
 };
diff --git a/sql/statement.cc b/sql/statement.cc
index 4f5e17f..985497e 100644
--- a/sql/statement.cc
+++ b/sql/statement.cc
@@ -149,7 +149,7 @@ bool Statement::BindString(int col, const std::string& val) {
                                    SQLITE_TRANSIENT));
 }
 
-bool Statement::BindString16(int col, const string16& value) {
+bool Statement::BindString16(int col, const base::string16& value) {
   return BindString(col, UTF16ToUTF8(value));
 }
 
@@ -235,12 +235,12 @@ std::string Statement::ColumnString(int col) const {
   return result;
 }
 
-string16 Statement::ColumnString16(int col) const {
+base::string16 Statement::ColumnString16(int col) const {
   if (!CheckValid())
-    return string16();
+    return base::string16();
 
   std::string s = ColumnString(col);
-  return !s.empty() ? UTF8ToUTF16(s) : string16();
+  return !s.empty() ? UTF8ToUTF16(s) : base::string16();
 }
 
 int Statement::ColumnByteLength(int col) const {
@@ -271,16 +271,16 @@ bool Statement::ColumnBlobAsString(int col, std::string* blob) {
   return true;
 }
 
-bool Statement::ColumnBlobAsString16(int col, string16* val) const {
+bool Statement::ColumnBlobAsString16(int col, base::string16* val) const {
   if (!CheckValid())
     return false;
 
   const void* data = ColumnBlob(col);
-  size_t len = ColumnByteLength(col) / sizeof(char16);
+  size_t len = ColumnByteLength(col) / sizeof(base::char16);
   val->resize(len);
   if (val->size() != len)
     return false;
-  val->assign(reinterpret_cast<const char16*>(data), len);
+  val->assign(reinterpret_cast<const base::char16*>(data), len);
   return true;
 }
 
diff --git a/sql/statement.h b/sql/statement.h
index acf89e7..e192e60 100644
--- a/sql/statement.h
+++ b/sql/statement.h
@@ -108,7 +108,7 @@ class SQL_EXPORT Statement {
   bool BindDouble(int col, double val);
   bool BindCString(int col, const char* val);
   bool BindString(int col, const std::string& val);
-  bool BindString16(int col, const string16& value);
+  bool BindString16(int col, const base::string16& value);
   bool BindBlob(int col, const void* value, int value_len);
 
   // Retrieving ----------------------------------------------------------------
@@ -131,7 +131,7 @@ class SQL_EXPORT Statement {
   int64 ColumnInt64(int col) const;
   double ColumnDouble(int col) const;
   std::string ColumnString(int col) const;
-  string16 ColumnString16(int col) const;
+  base::string16 ColumnString16(int col) const;
 
   // When reading a blob, you can get a raw pointer to the underlying data,
   // along with the length, or you can just ask us to copy the blob into a
@@ -139,7 +139,7 @@ class SQL_EXPORT Statement {
   int ColumnByteLength(int col) const;
   const void* ColumnBlob(int col) const;
   bool ColumnBlobAsString(int col, std::string* blob);
-  bool ColumnBlobAsString16(int col, string16* val) const;
+  bool ColumnBlobAsString16(int col, base::string16* val) const;
   bool ColumnBlobAsVector(int col, std::vector<char>* val) const;
   bool ColumnBlobAsVector(int col, std::vector<unsigned char>* val) const;