Use base namespace for string16 in chrome/browser.

This converts 200 more files.

TBR=sky

Review URL: https://codereview.chromium.org/108353004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239278 0039d316-1c4b-4281-b951-d872f2087c98

200 files changed, 802 insertions, 760 deletions

diff --git a/chrome/browser/hang_monitor/hung_plugin_action.cc b/chrome/browser/hang_monitor/hung_plugin_action.cc
index bc93207..8e248f8 100644
--- a/chrome/browser/hang_monitor/hung_plugin_action.cc
+++ b/chrome/browser/hang_monitor/hung_plugin_action.cc
@@ -38,7 +38,7 @@ enum GTalkPluginLogVersion {
 // version format is "major(1 digit).minor(1 digit).sub(1 or 2 digits)",
 // for example, "2.7.10" and "2.8.1". Converts the string to a number as
 // 10 * major + minor - kGTalkPluginLogMinVersion.
-GTalkPluginLogVersion GetGTalkPluginVersion(const string16& version) {
+GTalkPluginLogVersion GetGTalkPluginVersion(const base::string16& version) {
   int gtalk_plugin_version = GTALK_PLUGIN_VERSION_MIN;
   Version plugin_version;
   content::WebPluginInfo::CreateVersionFromString(version, &plugin_version);
@@ -81,8 +81,8 @@ bool HungPluginAction::OnHungWindowDetected(HWND hung_window,
 
   *action = HungWindowNotification::HUNG_WINDOW_IGNORE;
   if (top_level_window_process_id != hung_window_process_id) {
-    string16 plugin_name;
-    string16 plugin_version;
+    base::string16 plugin_name;
+    base::string16 plugin_version;
     GetPluginNameAndVersion(hung_window,
                             top_level_window_process_id,
                             &plugin_name,
@@ -99,9 +99,9 @@ bool HungPluginAction::OnHungWindowDetected(HWND hung_window,
       NOTREACHED() << "Terminated a hung plugin process.";
       *action = HungWindowNotification::HUNG_WINDOW_TERMINATE_PROCESS;
     } else {
-      const string16 title = l10n_util::GetStringUTF16(
+      const base::string16 title = l10n_util::GetStringUTF16(
           IDS_BROWSER_HANGMONITOR_TITLE);
-      const string16 message = l10n_util::GetStringFUTF16(
+      const base::string16 message = l10n_util::GetStringFUTF16(
           IDS_BROWSER_HANGMONITOR, plugin_name);
       // Before displaying the message box, invoke SendMessageCallback on the
       // hung window. If the callback ever hits, the window is not hung anymore
@@ -162,8 +162,8 @@ void HungPluginAction::OnWindowResponsive(HWND window) {
 
 bool HungPluginAction::GetPluginNameAndVersion(HWND plugin_window,
                                                DWORD browser_process_id,
-                                               string16* plugin_name,
-                                               string16* plugin_version) {
+                                               base::string16* plugin_name,
+                                               base::string16* plugin_version) {
   DCHECK(plugin_name);
   DCHECK(plugin_version);
   HWND window_to_check = plugin_window;
@@ -186,7 +186,7 @@ bool HungPluginAction::GetPluginNameAndVersion(HWND plugin_window,
 
 // static
 BOOL CALLBACK HungPluginAction::DismissMessageBox(HWND window, LPARAM ignore) {
-  string16 class_name = gfx::GetClassName(window);
+  base::string16 class_name = gfx::GetClassName(window);
   // #32770 is the dialog window class which is the window class of
   // the message box being displayed.
   if (class_name == L"#32770") {
diff --git a/chrome/browser/hang_monitor/hung_plugin_action.h b/chrome/browser/hang_monitor/hung_plugin_action.h
index 49b0b43..5ad00bb 100644
--- a/chrome/browser/hang_monitor/hung_plugin_action.h
+++ b/chrome/browser/hang_monitor/hung_plugin_action.h
@@ -39,8 +39,8 @@ class HungPluginAction : public HungWindowDetector::HungWindowNotification {
  protected:
   bool GetPluginNameAndVersion(HWND plugin_window,
                                DWORD browser_process_id,
-                               string16* plugin_name,
-                               string16* plugin_version);
+                               base::string16* plugin_name,
+                               base::string16* plugin_version);
   // The currently hung plugin window that we are prompting the user about
   HWND current_hung_plugin_window_;
 };
diff --git a/chrome/browser/mouseleave_browsertest.cc b/chrome/browser/mouseleave_browsertest.cc
index 47dd69db..726a651f 100644
--- a/chrome/browser/mouseleave_browsertest.cc
+++ b/chrome/browser/mouseleave_browsertest.cc
@@ -41,7 +41,7 @@ class MouseLeaveTest : public InProcessBrowserTest {
                                above_content_point.y());
 
     // Navigate to the test html page.
-    string16 load_expected_title(ASCIIToUTF16("onload"));
+    base::string16 load_expected_title(ASCIIToUTF16("onload"));
     content::TitleWatcher load_title_watcher(tab, load_expected_title);
     ui_test_utils::NavigateToURL(browser(), test_url);
     // Wait for the onload() handler to complete so we can do the
@@ -53,7 +53,7 @@ class MouseLeaveTest : public InProcessBrowserTest {
     ui_controls::SendMouseMove(in_content_point.x(), in_content_point.y());
 
     // Wait on the correct intermediate title.
-    string16 entered_expected_title(ASCIIToUTF16("entered"));
+    base::string16 entered_expected_title(ASCIIToUTF16("entered"));
     content::TitleWatcher entered_title_watcher(tab, entered_expected_title);
     EXPECT_EQ(entered_expected_title, entered_title_watcher.WaitAndGetTitle());
 
@@ -63,7 +63,7 @@ class MouseLeaveTest : public InProcessBrowserTest {
                                above_content_point.y());
 
     // Wait on the correct final value of the cookie.
-    string16 left_expected_title(ASCIIToUTF16("left"));
+    base::string16 left_expected_title(ASCIIToUTF16("left"));
     content::TitleWatcher left_title_watcher(tab, left_expected_title);
     EXPECT_EQ(left_expected_title, left_title_watcher.WaitAndGetTitle());
   }
diff --git a/chrome/browser/rlz/rlz.h b/chrome/browser/rlz/rlz.h
index d55e05c1..c7ab7989 100644
--- a/chrome/browser/rlz/rlz.h
+++ b/chrome/browser/rlz/rlz.h
@@ -73,7 +73,8 @@ class RLZTracker : public content::NotificationObserver {
   // Gets the RLZ value of the access point.
   // Returns false if the rlz string could not be obtained. In some cases
   // an empty string can be returned which is not an error.
-  static bool GetAccessPointRlz(rlz_lib::AccessPoint point, string16* rlz);
+  static bool GetAccessPointRlz(rlz_lib::AccessPoint point,
+                                base::string16* rlz);
 
   // Invoked during shutdown to clean up any state created by RLZTracker.
   static void CleanupRlz();
@@ -145,7 +146,7 @@ class RLZTracker : public content::NotificationObserver {
   void RecordFirstSearch(rlz_lib::AccessPoint point);
 
   // Implementation called from GetAccessPointRlz() static method.
-  bool GetAccessPointRlzImpl(rlz_lib::AccessPoint point, string16* rlz);
+  bool GetAccessPointRlzImpl(rlz_lib::AccessPoint point, base::string16* rlz);
 
   // Schedules the delayed initialization. This method is virtual to allow
   // tests to override how the scheduling is done.
@@ -174,8 +175,8 @@ class RLZTracker : public content::NotificationObserver {
   // Sends the financial ping to the RLZ servers. This method is virtual to
   // allow tests to override.
   virtual bool SendFinancialPing(const std::string& brand,
-                                 const string16& lang,
-                                 const string16& referral);
+                                 const base::string16& lang,
+                                 const base::string16& referral);
 
 #if defined(OS_CHROMEOS)
   // Implementation called from ClearRlzState static method.
@@ -209,7 +210,7 @@ class RLZTracker : public content::NotificationObserver {
   // The cache must be protected by a lock since it may be accessed from
   // the UI thread for reading and the IO thread for reading and/or writing.
   base::Lock cache_lock_;
-  std::map<rlz_lib::AccessPoint, string16> rlz_cache_;
+  std::map<rlz_lib::AccessPoint, base::string16> rlz_cache_;
 
   // Keeps track of whether the omnibox or host page have been used.
   bool omnibox_used_;
diff --git a/chrome/browser/rlz/rlz_unittest.cc b/chrome/browser/rlz/rlz_unittest.cc
index 198c62a..1dd7ba0 100644
--- a/chrome/browser/rlz/rlz_unittest.cc
+++ b/chrome/browser/rlz/rlz_unittest.cc
@@ -133,8 +133,8 @@ class TestRLZTracker : public RLZTracker {
 #endif
 
   virtual bool SendFinancialPing(const std::string& brand,
-                                 const string16& lang,
-                                 const string16& referral) OVERRIDE {
+                                 const base::string16& lang,
+                                 const base::string16& referral) OVERRIDE {
     // Don't ping the server during tests, just pretend as if we did.
     EXPECT_FALSE(brand.empty());
     pinged_brands_.insert(brand);
@@ -212,13 +212,13 @@ void RlzLibTest::SetReactivationBrand(const char* brand) {
 void RlzLibTest::SetRegistryBrandValue(const wchar_t* name,
                                        const char* brand) {
   BrowserDistribution* dist = BrowserDistribution::GetDistribution();
-  string16 reg_path = dist->GetStateKey();
+  base::string16 reg_path = dist->GetStateKey();
   RegKey key(HKEY_CURRENT_USER, reg_path.c_str(), KEY_SET_VALUE);
   if (*brand == 0) {
     LONG result = key.DeleteValue(name);
     ASSERT_TRUE(ERROR_SUCCESS == result || ERROR_FILE_NOT_FOUND == result);
   } else {
-    string16 brand16 = ASCIIToUTF16(brand);
+    base::string16 brand16 = ASCIIToUTF16(brand);
     ASSERT_EQ(ERROR_SUCCESS, key.WriteValue(name, brand16.c_str()));
   }
 }
@@ -583,7 +583,7 @@ TEST_F(RlzLibTest, GetAccessPointRlzOnIoThread) {
   // Set dummy RLZ string.
   rlz_lib::SetAccessPointRlz(RLZTracker::CHROME_OMNIBOX, kOmniboxRlzString);
 
-  string16 rlz;
+  base::string16 rlz;
 
   tracker_.set_assume_not_ui_thread(true);
   EXPECT_TRUE(RLZTracker::GetAccessPointRlz(RLZTracker::CHROME_OMNIBOX, &rlz));
@@ -594,7 +594,7 @@ TEST_F(RlzLibTest, GetAccessPointRlzNotOnIoThread) {
   // Set dummy RLZ string.
   rlz_lib::SetAccessPointRlz(RLZTracker::CHROME_OMNIBOX, kOmniboxRlzString);
 
-  string16 rlz;
+  base::string16 rlz;
 
   tracker_.set_assume_not_ui_thread(false);
   EXPECT_FALSE(RLZTracker::GetAccessPointRlz(RLZTracker::CHROME_OMNIBOX, &rlz));
@@ -604,7 +604,7 @@ TEST_F(RlzLibTest, GetAccessPointRlzIsCached) {
   // Set dummy RLZ string.
   rlz_lib::SetAccessPointRlz(RLZTracker::CHROME_OMNIBOX, kOmniboxRlzString);
 
-  string16 rlz;
+  base::string16 rlz;
 
   tracker_.set_assume_not_ui_thread(false);
   EXPECT_FALSE(RLZTracker::GetAccessPointRlz(RLZTracker::CHROME_OMNIBOX, &rlz));
@@ -623,7 +623,7 @@ TEST_F(RlzLibTest, PingUpdatesRlzCache) {
   rlz_lib::SetAccessPointRlz(RLZTracker::CHROME_OMNIBOX, kOmniboxRlzString);
   rlz_lib::SetAccessPointRlz(RLZTracker::CHROME_HOME_PAGE, kHomepageRlzString);
 
-  string16 rlz;
+  base::string16 rlz;
 
   // Prime the cache.
   tracker_.set_assume_not_ui_thread(true);
diff --git a/chrome/browser/ui/app_modal_dialogs/app_modal_dialog.cc b/chrome/browser/ui/app_modal_dialogs/app_modal_dialog.cc
index 77e9133..edd9457 100644
--- a/chrome/browser/ui/app_modal_dialogs/app_modal_dialog.cc
+++ b/chrome/browser/ui/app_modal_dialogs/app_modal_dialog.cc
@@ -14,7 +14,8 @@
 
 using content::WebContents;
 
-AppModalDialog::AppModalDialog(WebContents* web_contents, const string16& title)
+AppModalDialog::AppModalDialog(WebContents* web_contents,
+                               const base::string16& title)
     : title_(title),
       completed_(false),
       valid_(true),
diff --git a/chrome/browser/ui/app_modal_dialogs/app_modal_dialog.h b/chrome/browser/ui/app_modal_dialogs/app_modal_dialog.h
index 2da402f..28cf584 100644
--- a/chrome/browser/ui/app_modal_dialogs/app_modal_dialog.h
+++ b/chrome/browser/ui/app_modal_dialogs/app_modal_dialog.h
@@ -22,7 +22,8 @@ class AppModalDialog {
  public:
   // A union of data necessary to determine the type of message box to
   // show.
-  AppModalDialog(content::WebContents* web_contents, const string16& title);
+  AppModalDialog(content::WebContents* web_contents,
+                 const base::string16& title);
   virtual ~AppModalDialog();
 
   // Called by the AppModalDialogQueue to show this dialog.
@@ -38,7 +39,7 @@ class AppModalDialog {
   // TODO(beng): Get rid of this method.
   void CompleteDialog();
 
-  string16 title() const { return title_; }
+  base::string16 title() const { return title_; }
   NativeAppModalDialog* native_dialog() const { return native_dialog_; }
   content::WebContents* web_contents() const { return web_contents_; }
 
@@ -71,7 +72,7 @@ class AppModalDialog {
 
  private:
   // Information about the message box is held in the following variables.
-  string16 title_;
+  base::string16 title_;
 
   // True if CompleteDialog was called.
   bool completed_;
diff --git a/chrome/browser/ui/app_modal_dialogs/javascript_app_modal_dialog.cc b/chrome/browser/ui/app_modal_dialogs/javascript_app_modal_dialog.cc
index e678ad5..91e35b7 100644
--- a/chrome/browser/ui/app_modal_dialogs/javascript_app_modal_dialog.cc
+++ b/chrome/browser/ui/app_modal_dialogs/javascript_app_modal_dialog.cc
@@ -29,11 +29,13 @@ const int kMessageTextMaxRows = 32;
 const int kMessageTextMaxCols = 132;
 const int kDefaultPromptMaxRows = 24;
 const int kDefaultPromptMaxCols = 132;
-void EnforceMaxTextSize(const string16& in_string, string16* out_string) {
+void EnforceMaxTextSize(const base::string16& in_string,
+                        base::string16* out_string) {
   gfx::ElideRectangleString(in_string, kMessageTextMaxRows,
                            kMessageTextMaxCols, false, out_string);
 }
-void EnforceMaxPromptSize(const string16& in_string, string16* out_string) {
+void EnforceMaxPromptSize(const base::string16& in_string,
+                          base::string16* out_string) {
   gfx::ElideRectangleString(in_string, kDefaultPromptMaxRows,
                            kDefaultPromptMaxCols, false, out_string);
 }
@@ -42,10 +44,12 @@ void EnforceMaxPromptSize(const string16& in_string, string16* out_string) {
 // appropriately, but limit its overall length to something reasonable.
 const int kMessageTextMaxSize = 3000;
 const int kDefaultPromptMaxSize = 2000;
-void EnforceMaxTextSize(const string16& in_string, string16* out_string) {
+void EnforceMaxTextSize(const base::string16& in_string,
+                        base::string16* out_string) {
   gfx::ElideString(in_string, kMessageTextMaxSize, out_string);
 }
-void EnforceMaxPromptSize(const string16& in_string, string16* out_string) {
+void EnforceMaxPromptSize(const base::string16& in_string,
+                          base::string16* out_string) {
   gfx::ElideString(in_string, kDefaultPromptMaxSize, out_string);
 }
 #endif
@@ -59,10 +63,10 @@ ChromeJavaScriptDialogExtraData::ChromeJavaScriptDialogExtraData()
 JavaScriptAppModalDialog::JavaScriptAppModalDialog(
     WebContents* web_contents,
     ExtraDataMap* extra_data_map,
-    const string16& title,
+    const base::string16& title,
     content::JavaScriptMessageType javascript_message_type,
-    const string16& message_text,
-    const string16& default_prompt_text,
+    const base::string16& message_text,
+    const base::string16& default_prompt_text,
     bool display_suppress_checkbox,
     bool is_before_unload_dialog,
     bool is_reload,
@@ -108,7 +112,7 @@ void JavaScriptAppModalDialog::Invalidate() {
 
   AppModalDialog::Invalidate();
   if (!callback_.is_null()) {
-    callback_.Run(false, string16());
+    callback_.Run(false, base::string16());
     callback_.Reset();
   }
   if (native_dialog())
@@ -124,12 +128,12 @@ void JavaScriptAppModalDialog::OnCancel(bool suppress_js_messages) {
   // is a temporary workaround.
   CompleteDialog();
 
-  NotifyDelegate(false, string16(), suppress_js_messages);
+  NotifyDelegate(false, base::string16(), suppress_js_messages);
 }
 
-void JavaScriptAppModalDialog::OnAccept(const string16& prompt_text,
+void JavaScriptAppModalDialog::OnAccept(const base::string16& prompt_text,
                                         bool suppress_js_messages) {
-  string16 prompt_text_to_use = prompt_text;
+  base::string16 prompt_text_to_use = prompt_text;
   // This is only for testing.
   if (use_override_prompt_text_)
     prompt_text_to_use = override_prompt_text_;
@@ -139,17 +143,17 @@ void JavaScriptAppModalDialog::OnAccept(const string16& prompt_text,
 }
 
 void JavaScriptAppModalDialog::OnClose() {
-  NotifyDelegate(false, string16(), false);
+  NotifyDelegate(false, base::string16(), false);
 }
 
 void JavaScriptAppModalDialog::SetOverridePromptText(
-    const string16& override_prompt_text) {
+    const base::string16& override_prompt_text) {
   override_prompt_text_ = override_prompt_text;
   use_override_prompt_text_ = true;
 }
 
 void JavaScriptAppModalDialog::NotifyDelegate(bool success,
-                                              const string16& user_input,
+                                              const base::string16& user_input,
                                               bool suppress_js_messages) {
   if (!IsValid())
     return;
diff --git a/chrome/browser/ui/app_modal_dialogs/javascript_app_modal_dialog.h b/chrome/browser/ui/app_modal_dialogs/javascript_app_modal_dialog.h
index 38153fc..bd0dbb8 100644
--- a/chrome/browser/ui/app_modal_dialogs/javascript_app_modal_dialog.h
+++ b/chrome/browser/ui/app_modal_dialogs/javascript_app_modal_dialog.h
@@ -34,10 +34,10 @@ class JavaScriptAppModalDialog : public AppModalDialog {
   JavaScriptAppModalDialog(
       content::WebContents* web_contents,
       ExtraDataMap* extra_data_map,
-      const string16& title,
+      const base::string16& title,
       content::JavaScriptMessageType javascript_message_type,
-      const string16& message_text,
-      const string16& default_prompt_text,
+      const base::string16& message_text,
+      const base::string16& default_prompt_text,
       bool display_suppress_checkbox,
       bool is_before_unload_dialog,
       bool is_reload,
@@ -51,7 +51,7 @@ class JavaScriptAppModalDialog : public AppModalDialog {
 
   // Callbacks from NativeDialog when the user accepts or cancels the dialog.
   void OnCancel(bool suppress_js_messages);
-  void OnAccept(const string16& prompt_text, bool suppress_js_messages);
+  void OnAccept(const base::string16& prompt_text, bool suppress_js_messages);
 
   // NOTE: This is only called under Views, and should be removed. Any critical
   // work should be done in OnCancel or OnAccept. See crbug.com/63732 for more.
@@ -59,21 +59,21 @@ class JavaScriptAppModalDialog : public AppModalDialog {
 
   // Used only for testing. The dialog will use the given text when notifying
   // its delegate instead of whatever the UI reports.
-  void SetOverridePromptText(const string16& prompt_text);
+  void SetOverridePromptText(const base::string16& prompt_text);
 
   // Accessors
   content::JavaScriptMessageType javascript_message_type() const {
     return javascript_message_type_;
   }
-  string16 message_text() const { return message_text_; }
-  string16 default_prompt_text() const { return default_prompt_text_; }
+  base::string16 message_text() const { return message_text_; }
+  base::string16 default_prompt_text() const { return default_prompt_text_; }
   bool display_suppress_checkbox() const { return display_suppress_checkbox_; }
   bool is_before_unload_dialog() const { return is_before_unload_dialog_; }
   bool is_reload() const { return is_reload_; }
 
  private:
   // Notifies the delegate with the result of the dialog.
-  void NotifyDelegate(bool success, const string16& prompt_text,
+  void NotifyDelegate(bool success, const base::string16& prompt_text,
                       bool suppress_js_messages);
 
   // A map of extra Chrome-only data associated with the delegate_.
@@ -82,8 +82,8 @@ class JavaScriptAppModalDialog : public AppModalDialog {
 
   // Information about the message box is held in the following variables.
   const content::JavaScriptMessageType javascript_message_type_;
-  string16 message_text_;
-  string16 default_prompt_text_;
+  base::string16 message_text_;
+  base::string16 default_prompt_text_;
   bool display_suppress_checkbox_;
   bool is_before_unload_dialog_;
   bool is_reload_;
@@ -92,7 +92,7 @@ class JavaScriptAppModalDialog : public AppModalDialog {
 
   // Used only for testing. Specifies alternative prompt text that should be
   // used when notifying the delegate, if |use_override_prompt_text_| is true.
-  string16 override_prompt_text_;
+  base::string16 override_prompt_text_;
   bool use_override_prompt_text_;
 
   DISALLOW_COPY_AND_ASSIGN(JavaScriptAppModalDialog);
diff --git a/chrome/browser/ui/app_modal_dialogs/javascript_dialog_manager.cc b/chrome/browser/ui/app_modal_dialogs/javascript_dialog_manager.cc
index 833e194..dc10bcc 100644
--- a/chrome/browser/ui/app_modal_dialogs/javascript_dialog_manager.cc
+++ b/chrome/browser/ui/app_modal_dialogs/javascript_dialog_manager.cc
@@ -47,21 +47,21 @@ class ChromeJavaScriptDialogManager : public JavaScriptDialogManager,
       const GURL& origin_url,
       const std::string& accept_lang,
       content::JavaScriptMessageType 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;
+      const base::string16* prompt_override) OVERRIDE;
 
   virtual void CancelActiveAndPendingDialogs(
       WebContents* web_contents) OVERRIDE;
@@ -78,7 +78,7 @@ class ChromeJavaScriptDialogManager : public JavaScriptDialogManager,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
-  string16 GetTitle(const GURL& origin_url,
+  base::string16 GetTitle(const GURL& origin_url,
                     const std::string& accept_lang,
                     bool is_alert);
 
@@ -86,7 +86,7 @@ class ChromeJavaScriptDialogManager : public JavaScriptDialogManager,
   // passing it onto the original callback.
   void OnDialogClosed(DialogClosedCallback callback,
                       bool success,
-                      const string16& user_input);
+                      const base::string16& user_input);
 
   // Mapping between the WebContents and their extra data. The key
   // is a void* because the pointer is just a cookie and is never dereferenced.
@@ -132,8 +132,8 @@ void ChromeJavaScriptDialogManager::RunJavaScriptDialog(
     const GURL& origin_url,
     const std::string& accept_lang,
     content::JavaScriptMessageType 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)  {
   *did_suppress_message = false;
@@ -160,7 +160,7 @@ void ChromeJavaScriptDialogManager::RunJavaScriptDialog(
   }
 
   bool is_alert = message_type == content::JAVASCRIPT_MESSAGE_TYPE_ALERT;
-  string16 dialog_title = GetTitle(origin_url, accept_lang, is_alert);
+  base::string16 dialog_title = GetTitle(origin_url, accept_lang, is_alert);
 
   if (extension_host_)
     extension_host_->WillRunJavaScriptDialog();
@@ -181,15 +181,15 @@ void ChromeJavaScriptDialogManager::RunJavaScriptDialog(
 
 void ChromeJavaScriptDialogManager::RunBeforeUnloadDialog(
     WebContents* web_contents,
-    const string16& message_text,
+    const base::string16& message_text,
     bool is_reload,
     const DialogClosedCallback& callback) {
-  const string16 title = l10n_util::GetStringUTF16(is_reload ?
+  const base::string16 title = l10n_util::GetStringUTF16(is_reload ?
       IDS_BEFORERELOAD_MESSAGEBOX_TITLE : IDS_BEFOREUNLOAD_MESSAGEBOX_TITLE);
-  const string16 footer = l10n_util::GetStringUTF16(is_reload ?
+  const base::string16 footer = l10n_util::GetStringUTF16(is_reload ?
       IDS_BEFORERELOAD_MESSAGEBOX_FOOTER : IDS_BEFOREUNLOAD_MESSAGEBOX_FOOTER);
 
-  string16 full_message = message_text + ASCIIToUTF16("\n\n") + footer;
+  base::string16 full_message = message_text + ASCIIToUTF16("\n\n") + footer;
 
   if (extension_host_)
     extension_host_->WillRunJavaScriptDialog();
@@ -200,7 +200,7 @@ void ChromeJavaScriptDialogManager::RunBeforeUnloadDialog(
       title,
       content::JAVASCRIPT_MESSAGE_TYPE_CONFIRM,
       full_message,
-      string16(),  // default_prompt_text
+      base::string16(),  // default_prompt_text
       false,       // display_suppress_checkbox
       true,        // is_before_unload_dialog
       is_reload,
@@ -211,7 +211,7 @@ void ChromeJavaScriptDialogManager::RunBeforeUnloadDialog(
 bool ChromeJavaScriptDialogManager::HandleJavaScriptDialog(
     WebContents* web_contents,
     bool accept,
-    const string16* prompt_override) {
+    const base::string16* prompt_override) {
   AppModalDialogQueue* dialog_queue = AppModalDialogQueue::GetInstance();
   if (!dialog_queue->HasActiveDialog() ||
       !dialog_queue->active_dialog()->IsJavaScriptModalDialog() ||
@@ -268,7 +268,7 @@ string16 ChromeJavaScriptDialogManager::GetTitle(const GURL& origin_url,
 
   // Otherwise, return the formatted URL.
   // In this case, force URL to have LTR directionality.
-  string16 url_string = net::FormatUrl(origin_url, accept_lang);
+  base::string16 url_string = net::FormatUrl(origin_url, accept_lang);
   return l10n_util::GetStringFUTF16(
       is_alert ? IDS_JAVASCRIPT_ALERT_TITLE
       : IDS_JAVASCRIPT_MESSAGEBOX_TITLE,
@@ -291,7 +291,7 @@ void ChromeJavaScriptDialogManager::CancelActiveAndPendingDialogs(
 void ChromeJavaScriptDialogManager::OnDialogClosed(
     DialogClosedCallback callback,
     bool success,
-    const string16& user_input) {
+    const base::string16& user_input) {
   if (extension_host_)
     extension_host_->DidCloseJavaScriptDialog();
   callback.Run(success, user_input);
diff --git a/chrome/browser/ui/ash/chrome_shell_delegate.h b/chrome/browser/ui/ash/chrome_shell_delegate.h
index 1fd08b59..ce73296 100644
--- a/chrome/browser/ui/ash/chrome_shell_delegate.h
+++ b/chrome/browser/ui/ash/chrome_shell_delegate.h
@@ -60,7 +60,7 @@ class ChromeShellDelegate : public ash::ShellDelegate,
   virtual void RecordUserMetricsAction(ash::UserMetricsAction action) OVERRIDE;
   virtual ui::MenuModel* CreateContextMenu(aura::Window* root) OVERRIDE;
   virtual ash::RootWindowHostFactory* CreateRootWindowHostFactory() OVERRIDE;
-  virtual string16 GetProductName() const OVERRIDE;
+  virtual base::string16 GetProductName() const OVERRIDE;
 
   // content::NotificationObserver override:
   virtual void Observe(int type,
diff --git a/chrome/browser/ui/ash/launcher/app_shortcut_launcher_item_controller.cc b/chrome/browser/ui/ash/launcher/app_shortcut_launcher_item_controller.cc
index 4f6ddd3..c3009e4 100644
--- a/chrome/browser/ui/ash/launcher/app_shortcut_launcher_item_controller.cc
+++ b/chrome/browser/ui/ash/launcher/app_shortcut_launcher_item_controller.cc
@@ -151,7 +151,7 @@ AppShortcutLauncherItemController::GetApplicationList(int event_flags) {
     content::WebContents* web_contents = content_list[i];
     // Get the icon.
     gfx::Image app_icon = launcher_controller()->GetAppListIcon(web_contents);
-    string16 title = launcher_controller()->GetAppListTitle(web_contents);
+    base::string16 title = launcher_controller()->GetAppListTitle(web_contents);
     items.push_back(new ChromeLauncherAppMenuItemTab(
         title, &app_icon, web_contents, i == 0));
   }
diff --git a/chrome/browser/ui/ash/launcher/browser_shortcut_launcher_item_controller.cc b/chrome/browser/ui/ash/launcher/browser_shortcut_launcher_item_controller.cc
index 78339ec..31a65fc 100644
--- a/chrome/browser/ui/ash/launcher/browser_shortcut_launcher_item_controller.cc
+++ b/chrome/browser/ui/ash/launcher/browser_shortcut_launcher_item_controller.cc
@@ -180,7 +180,7 @@ BrowserShortcutLauncherItemController::GetApplicationList(int event_flags) {
       content::WebContents* web_contents =
           tab_strip->GetWebContentsAt(tab_strip->active_index());
       gfx::Image app_icon = GetBrowserListIcon(web_contents);
-      string16 title = GetBrowserListTitle(web_contents);
+      base::string16 title = GetBrowserListTitle(web_contents);
       items.push_back(new ChromeLauncherAppMenuItemBrowser(
           title, &app_icon, browser, items.size() == 1));
     } else {
@@ -189,7 +189,8 @@ BrowserShortcutLauncherItemController::GetApplicationList(int event_flags) {
             tab_strip->GetWebContentsAt(index);
         gfx::Image app_icon =
             launcher_controller()->GetAppListIcon(web_contents);
-        string16 title = launcher_controller()->GetAppListTitle(web_contents);
+        base::string16 title =
+            launcher_controller()->GetAppListTitle(web_contents);
         // Check if we need to insert a separator in front.
         bool leading_separator = !index;
         items.push_back(new ChromeLauncherAppMenuItemTab(
@@ -260,7 +261,7 @@ gfx::Image BrowserShortcutLauncherItemController::GetBrowserListIcon(
 
 string16 BrowserShortcutLauncherItemController::GetBrowserListTitle(
     content::WebContents* web_contents) const {
-  string16 title = web_contents->GetTitle();
+  base::string16 title = web_contents->GetTitle();
   if (!title.empty())
     return title;
   return l10n_util::GetStringUTF16(IDS_NEW_TAB_TITLE);
diff --git a/chrome/browser/ui/ash/launcher/browser_shortcut_launcher_item_controller.h b/chrome/browser/ui/ash/launcher/browser_shortcut_launcher_item_controller.h
index 222bd5e..69fff4a 100644
--- a/chrome/browser/ui/ash/launcher/browser_shortcut_launcher_item_controller.h
+++ b/chrome/browser/ui/ash/launcher/browser_shortcut_launcher_item_controller.h
@@ -52,7 +52,7 @@ class BrowserShortcutLauncherItemController : public LauncherItemController {
 
   // Get the title for the browser list entry for |web_contents|.
   // If |web_contents| has not loaded, returns "Net Tab".
-  string16 GetBrowserListTitle(content::WebContents* web_contents) const;
+  base::string16 GetBrowserListTitle(content::WebContents* web_contents) const;
 
   // Check if the given |web_contents| is in incognito mode.
   bool IsIncognito(content::WebContents* web_contents) const;
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item.cc b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item.cc
index a337320..6d2e9c2 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item.cc
@@ -5,7 +5,7 @@
 #include "chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item.h"
 
 ChromeLauncherAppMenuItem::ChromeLauncherAppMenuItem(
-    const string16 title,
+    const base::string16 title,
     const gfx::Image* icon,
     bool has_leading_separator)
     : title_(title),
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item.h b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item.h
index 2757a76..0612db3 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item.h
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item.h
@@ -13,14 +13,14 @@
 class ChromeLauncherAppMenuItem {
  public:
   // To insert a separator before this item set |has_leading_separator|.
-  ChromeLauncherAppMenuItem(const string16 title,
+  ChromeLauncherAppMenuItem(const base::string16 title,
                             const gfx::Image* icon,
                             bool has_leading_separator);
 
   virtual ~ChromeLauncherAppMenuItem();
 
   // Retrieves the title for this menu option.
-  const string16& title() const { return title_; }
+  const base::string16& title() const { return title_; }
 
   // Retrieves the icon for this menu option.
   const gfx::Image& icon() const { return icon_; }
@@ -40,7 +40,7 @@ class ChromeLauncherAppMenuItem {
   virtual void Execute(int event_flags);
 
  private:
-  const string16 title_;
+  const base::string16 title_;
   const gfx::Image icon_;
 
   // True if the item has a separator in front of it.
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_browser.cc b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_browser.cc
index 903d36e..3f38fb4 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_browser.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_browser.cc
@@ -14,7 +14,7 @@
 #include "ui/events/event_constants.h"
 
 ChromeLauncherAppMenuItemBrowser::ChromeLauncherAppMenuItemBrowser(
-    const string16 title,
+    const base::string16 title,
     const gfx::Image* icon,
     Browser* browser,
     bool has_leading_separator)
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_browser.h b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_browser.h
index 0e330ec..3ddd416 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_browser.h
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_browser.h
@@ -18,7 +18,7 @@ class Browser;
 class ChromeLauncherAppMenuItemBrowser : public content::NotificationObserver,
                                          public ChromeLauncherAppMenuItem {
  public:
-  ChromeLauncherAppMenuItemBrowser(const string16 title,
+  ChromeLauncherAppMenuItemBrowser(const base::string16 title,
                                    const gfx::Image* icon,
                                    Browser* browser,
                                    bool has_leading_separator);
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_tab.cc b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_tab.cc
index 3b9864f..b1ce6d6 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_tab.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_tab.cc
@@ -12,7 +12,7 @@
 #include "ui/events/event_constants.h"
 
 ChromeLauncherAppMenuItemTab::ChromeLauncherAppMenuItemTab(
-    const string16 title,
+    const base::string16 title,
     const gfx::Image* icon,
     content::WebContents* content,
     bool has_leading_separator)
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_tab.h b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_tab.h
index 9c0a0f5..c40c52c 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_tab.h
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_tab.h
@@ -22,7 +22,7 @@ class ChromeLauncherAppMenuItemTab
     : public ChromeLauncherAppMenuItem,
       public content::WebContentsObserver {
  public:
-  ChromeLauncherAppMenuItemTab(const string16 title,
+  ChromeLauncherAppMenuItemTab(const base::string16 title,
                                const gfx::Image* icon,
                                content::WebContents* content,
                                bool has_leading_separator);
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_v2app.cc b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_v2app.cc
index fe6546c..8c812d6 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_v2app.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_v2app.cc
@@ -7,7 +7,7 @@
 #include "chrome/browser/ui/ash/launcher/chrome_launcher_controller.h"
 
 ChromeLauncherAppMenuItemV2App::ChromeLauncherAppMenuItemV2App(
-    const string16 title,
+    const base::string16 title,
     const gfx::Image* icon,
     const std::string& app_id,
     ChromeLauncherController* launcher_controller,
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_v2app.h b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_v2app.h
index c195b0e..775bc43 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_v2app.h
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_app_menu_item_v2app.h
@@ -21,7 +21,7 @@ class ChromeLauncherController;
 class ChromeLauncherAppMenuItemV2App : public ChromeLauncherAppMenuItem {
  public:
   ChromeLauncherAppMenuItemV2App(
-      const string16 title,
+      const base::string16 title,
       const gfx::Image* icon,
       const std::string& app_id,
       ChromeLauncherController* launcher_controller,
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc b/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
index 9c7a2ed..b91bd0da8 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
@@ -1350,7 +1350,7 @@ gfx::Image ChromeLauncherController::GetAppListIcon(
 
 string16 ChromeLauncherController::GetAppListTitle(
     content::WebContents* web_contents) const {
-  string16 title = web_contents->GetTitle();
+  base::string16 title = web_contents->GetTitle();
   if (!title.empty())
     return title;
   WebContentsToAppIDMap::const_iterator iter =
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller.h b/chrome/browser/ui/ash/launcher/chrome_launcher_controller.h
index 35d93aa3..2873da4 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller.h
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller.h
@@ -375,7 +375,7 @@ class ChromeLauncherController : public ash::LauncherDelegate,
 
   // Get the title for the applicatoin list entry for |web_contents|.
   // If |web_contents| has not loaded, returns "Net Tab".
-  string16 GetAppListTitle(content::WebContents* web_contents) const;
+  base::string16 GetAppListTitle(content::WebContents* web_contents) const;
 
   // Returns the LauncherItemController of BrowserShortcut.
   BrowserShortcutLauncherItemController*
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_unittest.cc b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_unittest.cc
index 75b6e6d..f8dcd69 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_unittest.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_unittest.cc
@@ -233,7 +233,7 @@ class TestV2AppLauncherItemController : public LauncherItemController {
   virtual bool Activate(ash::LaunchSource source) OVERRIDE { return false; }
   virtual void Close() OVERRIDE {}
   virtual bool ItemSelected(const ui::Event& event) OVERRIDE { return false; }
-  virtual string16 GetTitle() OVERRIDE { return string16(); }
+  virtual base::string16 GetTitle() OVERRIDE { return base::string16(); }
   virtual ChromeLauncherAppMenuItems GetApplicationList(
       int event_flags) OVERRIDE {
     ChromeLauncherAppMenuItems items;
@@ -2055,7 +2055,7 @@ TEST_F(ChromeLauncherControllerTest, PendingInsertionOrder) {
 bool CheckMenuCreation(ChromeLauncherController* controller,
                        const ash::LauncherItem& item,
                        size_t expected_items,
-                       string16 title[],
+                       base::string16 title[],
                        bool is_browser) {
   ChromeLauncherAppMenuItems items = controller->GetApplicationList(item, 0);
   // A new behavior has been added: Only show menus if there is at least one
@@ -2111,9 +2111,9 @@ TEST_F(ChromeLauncherControllerTest, BrowserMenuGeneration) {
   // Now make the created browser() visible by adding it to the active browser
   // list.
   BrowserList::SetLastActive(browser());
-  string16 title1 = ASCIIToUTF16("Test1");
+  base::string16 title1 = ASCIIToUTF16("Test1");
   NavigateAndCommitActiveTabWithTitle(browser(), GURL("http://test1"), title1);
-  string16 one_menu_item[] = { title1 };
+  base::string16 one_menu_item[] = { title1 };
 
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_browser, 1, one_menu_item, true));
@@ -2124,13 +2124,13 @@ TEST_F(ChromeLauncherControllerTest, BrowserMenuGeneration) {
       chrome::CreateBrowserWithTestWindowForParams(&ash_params));
   chrome::NewTab(browser2.get());
   BrowserList::SetLastActive(browser2.get());
-  string16 title2 = ASCIIToUTF16("Test2");
+  base::string16 title2 = ASCIIToUTF16("Test2");
   NavigateAndCommitActiveTabWithTitle(browser2.get(), GURL("http://test2"),
                                       title2);
 
   // Check that the list contains now two entries - make furthermore sure that
   // the active item is the first entry.
-  string16 two_menu_items[] = {title1, title2};
+  base::string16 two_menu_items[] = {title1, title2};
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_browser, 2, two_menu_items, true));
 
@@ -2158,9 +2158,9 @@ TEST_F(MultiProfileMultiBrowserShelfLayoutChromeLauncherControllerTest,
 
   // Show the created |browser()| by adding it to the active browser list.
   BrowserList::SetLastActive(browser());
-  string16 title1 = ASCIIToUTF16("Test1");
+  base::string16 title1 = ASCIIToUTF16("Test1");
   NavigateAndCommitActiveTabWithTitle(browser(), GURL("http://test1"), title1);
-  string16 one_menu_item1[] = { title1 };
+  base::string16 one_menu_item1[] = { title1 };
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_browser, 1, one_menu_item1, true));
 
@@ -2170,7 +2170,7 @@ TEST_F(MultiProfileMultiBrowserShelfLayoutChromeLauncherControllerTest,
   TestingProfile* profile2 = CreateMultiUserProfile(user2);
   scoped_ptr<Browser> browser2(
       CreateBrowserAndTabWithProfile(profile2, user2, "http://test2"));
-  string16 one_menu_item2[] = { ASCIIToUTF16(user2) };
+  base::string16 one_menu_item2[] = { ASCIIToUTF16(user2) };
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_browser, 1, one_menu_item1, true));
 
@@ -2227,16 +2227,16 @@ TEST_F(ChromeLauncherControllerTest, V1AppMenuGeneration) {
       launcher_controller_.get(), item_gmail, 0, NULL, false));
 
   // Set the gmail URL to a new tab.
-  string16 title1 = ASCIIToUTF16("Test1");
+  base::string16 title1 = ASCIIToUTF16("Test1");
   NavigateAndCommitActiveTabWithTitle(browser(), GURL(gmail_url), title1);
 
-  string16 one_menu_item[] = { title1 };
+  base::string16 one_menu_item[] = { title1 };
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_gmail, 1, one_menu_item, false));
 
   // Create one empty tab.
   chrome::NewTab(browser());
-  string16 title2 = ASCIIToUTF16("Test2");
+  base::string16 title2 = ASCIIToUTF16("Test2");
   NavigateAndCommitActiveTabWithTitle(
       browser(),
       GURL("https://bla"),
@@ -2244,15 +2244,15 @@ TEST_F(ChromeLauncherControllerTest, V1AppMenuGeneration) {
 
   // and another one with another gmail instance.
   chrome::NewTab(browser());
-  string16 title3 = ASCIIToUTF16("Test3");
+  base::string16 title3 = ASCIIToUTF16("Test3");
   NavigateAndCommitActiveTabWithTitle(browser(), GURL(gmail_url), title3);
-  string16 two_menu_items[] = {title1, title3};
+  base::string16 two_menu_items[] = {title1, title3};
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_gmail, 2, two_menu_items, false));
 
   // Even though the item is in the V1 app list, it should also be in the
   // browser list.
-  string16 browser_menu_item[] = {title3};
+  base::string16 browser_menu_item[] = {title3};
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_browser, 1, browser_menu_item, false));
 
@@ -2262,7 +2262,7 @@ TEST_F(ChromeLauncherControllerTest, V1AppMenuGeneration) {
 
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_gmail, 0, NULL, false));
-  string16 browser_menu_item2[] = { title2 };
+  base::string16 browser_menu_item2[] = { title2 };
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_browser, 1, browser_menu_item2, false));
 }
@@ -2297,10 +2297,10 @@ TEST_F(MultiProfileMultiBrowserShelfLayoutChromeLauncherControllerTest,
       launcher_controller_.get(), item_gmail, 0, NULL, false));
 
   // Set the gmail URL to a new tab.
-  string16 title1 = ASCIIToUTF16("Test1");
+  base::string16 title1 = ASCIIToUTF16("Test1");
   NavigateAndCommitActiveTabWithTitle(browser(), GURL(gmail_url), title1);
 
-  string16 one_menu_item[] = { title1 };
+  base::string16 one_menu_item[] = { title1 };
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_gmail, 1, one_menu_item, false));
 
@@ -2405,17 +2405,17 @@ TEST_F(ChromeLauncherControllerTest, V1AppMenuExecution) {
   ash::LauncherID gmail_id = model_->next_id();
   extension_service_->AddExtension(extension3_.get());
   launcher_controller_->SetRefocusURLPatternForTest(gmail_id, GURL(gmail_url));
-  string16 title1 = ASCIIToUTF16("Test1");
+  base::string16 title1 = ASCIIToUTF16("Test1");
   NavigateAndCommitActiveTabWithTitle(browser(), GURL(gmail_url), title1);
   chrome::NewTab(browser());
-  string16 title2 = ASCIIToUTF16("Test2");
+  base::string16 title2 = ASCIIToUTF16("Test2");
   NavigateAndCommitActiveTabWithTitle(browser(), GURL(gmail_url), title2);
 
   // Check that the menu is properly set.
   ash::LauncherItem item_gmail;
   item_gmail.type = ash::TYPE_APP_SHORTCUT;
   item_gmail.id = gmail_id;
-  string16 two_menu_items[] = {title1, title2};
+  base::string16 two_menu_items[] = {title1, title2};
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_gmail, 2, two_menu_items, false));
   EXPECT_EQ(1, browser()->tab_strip_model()->active_index());
@@ -2454,17 +2454,17 @@ TEST_F(ChromeLauncherControllerTest, V1AppMenuDeletionExecution) {
   ash::LauncherID gmail_id = model_->next_id();
   extension_service_->AddExtension(extension3_.get());
   launcher_controller_->SetRefocusURLPatternForTest(gmail_id, GURL(gmail_url));
-  string16 title1 = ASCIIToUTF16("Test1");
+  base::string16 title1 = ASCIIToUTF16("Test1");
   NavigateAndCommitActiveTabWithTitle(browser(), GURL(gmail_url), title1);
   chrome::NewTab(browser());
-  string16 title2 = ASCIIToUTF16("Test2");
+  base::string16 title2 = ASCIIToUTF16("Test2");
   NavigateAndCommitActiveTabWithTitle(browser(), GURL(gmail_url), title2);
 
   // Check that the menu is properly set.
   ash::LauncherItem item_gmail;
   item_gmail.type = ash::TYPE_APP_SHORTCUT;
   item_gmail.id = gmail_id;
-  string16 two_menu_items[] = {title1, title2};
+  base::string16 two_menu_items[] = {title1, title2};
   EXPECT_TRUE(CheckMenuCreation(
       launcher_controller_.get(), item_gmail, 2, two_menu_items, false));
 
@@ -2548,7 +2548,7 @@ TEST_F(ChromeLauncherControllerTest, GmailMatching) {
 
   // Create a Gmail browser tab.
   chrome::NewTab(browser());
-  string16 title = ASCIIToUTF16("Test");
+  base::string16 title = ASCIIToUTF16("Test");
   NavigateAndCommitActiveTabWithTitle(browser(), GURL(gmail_url), title);
   content::WebContents* content =
       browser()->tab_strip_model()->GetActiveWebContents();
@@ -2580,7 +2580,7 @@ TEST_F(ChromeLauncherControllerTest, GmailOfflineMatching) {
 
   // Create a Gmail browser tab.
   chrome::NewTab(browser());
-  string16 title = ASCIIToUTF16("Test");
+  base::string16 title = ASCIIToUTF16("Test");
   NavigateAndCommitActiveTabWithTitle(browser(),
                                       GURL(offline_gmail_url),
                                       title);
diff --git a/chrome/browser/ui/ash/launcher/launcher_context_menu.cc b/chrome/browser/ui/ash/launcher/launcher_context_menu.cc
index 620ca95..ea15a95 100644
--- a/chrome/browser/ui/ash/launcher/launcher_context_menu.cc
+++ b/chrome/browser/ui/ash/launcher/launcher_context_menu.cc
@@ -73,7 +73,7 @@ void LauncherContextMenu::Init() {
         item_.type == ash::TYPE_WINDOWED_APP) {
       // V1 apps can be started from the menu - but V2 apps should not.
       if  (!controller_->IsPlatformApp(item_.id)) {
-        AddItem(MENU_OPEN_NEW, string16());
+        AddItem(MENU_OPEN_NEW, base::string16());
         AddSeparator(ui::NORMAL_SEPARATOR);
       }
       AddItem(
@@ -129,7 +129,7 @@ void LauncherContextMenu::Init() {
       if (!app_id.empty()) {
         int index = 0;
         extension_items_->AppendExtensionItems(
-            app_id, string16(), &index);
+            app_id, base::string16(), &index);
         AddSeparator(ui::NORMAL_SEPARATOR);
       }
     }
@@ -175,7 +175,7 @@ string16 LauncherContextMenu::GetLabelForCommandId(int command_id) const {
     }
   }
   NOTREACHED();
-  return string16();
+  return base::string16();
 }
 
 bool LauncherContextMenu::IsCommandIdChecked(int command_id) const {
diff --git a/chrome/browser/ui/ash/launcher/launcher_context_menu.h b/chrome/browser/ui/ash/launcher/launcher_context_menu.h
index 5b89dfb..bf73f1f 100644
--- a/chrome/browser/ui/ash/launcher/launcher_context_menu.h
+++ b/chrome/browser/ui/ash/launcher/launcher_context_menu.h
@@ -43,7 +43,7 @@ class LauncherContextMenu : public ui::SimpleMenuModel,
 
   // ui::SimpleMenuModel::Delegate overrides:
   virtual bool IsItemForCommandIdDynamic(int command_id) const OVERRIDE;
-  virtual string16 GetLabelForCommandId(int command_id) const OVERRIDE;
+  virtual base::string16 GetLabelForCommandId(int command_id) const OVERRIDE;
   virtual bool IsCommandIdChecked(int command_id) const OVERRIDE;
   virtual bool IsCommandIdEnabled(int command_id) const OVERRIDE;
   virtual bool GetAcceleratorForCommandId(
diff --git a/chrome/browser/ui/ash/launcher/launcher_item_controller.cc b/chrome/browser/ui/ash/launcher/launcher_item_controller.cc
index e97b9c6..b205cdb 100644
--- a/chrome/browser/ui/ash/launcher/launcher_item_controller.cc
+++ b/chrome/browser/ui/ash/launcher/launcher_item_controller.cc
@@ -32,11 +32,11 @@ const std::string& LauncherItemController::app_id() const {
 
 string16 LauncherItemController::GetAppTitle() const {
   if (app_id_.empty())
-    return string16();
+    return base::string16();
   const extensions::Extension* extension =
       launcher_controller_->profile()->GetExtensionService()->
       GetInstalledExtension(app_id_);
-  return extension ? UTF8ToUTF16(extension->name()) : string16();
+  return extension ? UTF8ToUTF16(extension->name()) : base::string16();
 }
 
 ash::LauncherItemType LauncherItemController::GetLauncherItemType() const {
diff --git a/chrome/browser/ui/ash/launcher/launcher_item_controller.h b/chrome/browser/ui/ash/launcher/launcher_item_controller.h
index 9654461..633440f 100644
--- a/chrome/browser/ui/ash/launcher/launcher_item_controller.h
+++ b/chrome/browser/ui/ash/launcher/launcher_item_controller.h
@@ -90,7 +90,7 @@ class LauncherItemController : public ash::ShelfItemDelegate {
  protected:
   // Helper function to return the title associated with |app_id_|.
   // Returns an empty title if no matching extension can be found.
-  string16 GetAppTitle() const;
+  base::string16 GetAppTitle() const;
 
  private:
   const Type type_;
diff --git a/chrome/browser/ui/ash/launcher/shell_window_launcher_item_controller.cc b/chrome/browser/ui/ash/launcher/shell_window_launcher_item_controller.cc
index 07ce41a..4a0ca09 100644
--- a/chrome/browser/ui/ash/launcher/shell_window_launcher_item_controller.cc
+++ b/chrome/browser/ui/ash/launcher/shell_window_launcher_item_controller.cc
@@ -214,7 +214,7 @@ base::string16 ShellWindowLauncherItemController::GetTitle() {
   if (type() == TYPE_APP_PANEL && !shell_windows_.empty()) {
     ShellWindow* shell_window = shell_windows_.front();
     if (shell_window->web_contents()) {
-      string16 title = shell_window->web_contents()->GetTitle();
+      base::string16 title = shell_window->web_contents()->GetTitle();
       if (!title.empty())
         return title;
     }
diff --git a/chrome/browser/ui/ash/screenshot_taker.cc b/chrome/browser/ui/ash/screenshot_taker.cc
index 55fc14a..0828f87 100644
--- a/chrome/browser/ui/ash/screenshot_taker.cc
+++ b/chrome/browser/ui/ash/screenshot_taker.cc
@@ -513,12 +513,12 @@ Notification* ScreenshotTaker::CreateNotification(
   // We cancel a previous screenshot notification, if any, to ensure we get
   // a fresh notification pop-up.
   g_browser_process->notification_ui_manager()->CancelById(notification_id);
-  const string16 replace_id(UTF8ToUTF16(notification_id));
+  const base::string16 replace_id(UTF8ToUTF16(notification_id));
   bool success =
       (screenshot_result == ScreenshotTakerObserver::SCREENSHOT_SUCCESS);
   message_center::RichNotificationData optional_field;
   if (success) {
-    const string16 label = l10n_util::GetStringUTF16(
+    const base::string16 label = l10n_util::GetStringUTF16(
         IDS_MESSAGE_CENTER_NOTIFICATION_BUTTON_COPY_SCREENSHOT_TO_CLIPBOARD);
     optional_field.buttons.push_back(message_center::ButtonInfo(label));
   }
diff --git a/chrome/browser/ui/ash/system_tray_delegate_win.cc b/chrome/browser/ui/ash/system_tray_delegate_win.cc
index 31a09a2..90069ca 100644
--- a/chrome/browser/ui/ash/system_tray_delegate_win.cc
+++ b/chrome/browser/ui/ash/system_tray_delegate_win.cc
@@ -72,20 +72,21 @@ class SystemTrayDelegateWin : public ash::SystemTrayDelegate,
     return std::string();
   }
 
-  virtual const string16 GetEnterpriseMessage() const OVERRIDE {
-    return string16();
+  virtual const base::string16 GetEnterpriseMessage() const OVERRIDE {
+    return base::string16();
   }
 
   virtual const std::string GetLocallyManagedUserManager() const OVERRIDE {
     return std::string();
   }
 
-  virtual const string16 GetLocallyManagedUserManagerName() const OVERRIDE {
-    return string16();
+  virtual const base::string16 GetLocallyManagedUserManagerName() const
+        OVERRIDE {
+    return base::string16();
   }
 
-  virtual const string16 GetLocallyManagedUserMessage() const OVERRIDE {
-    return string16();
+  virtual const base::string16 GetLocallyManagedUserMessage() const OVERRIDE {
+    return base::string16();
   }
 
   virtual bool SystemShouldUpgrade() const OVERRIDE {
diff --git a/chrome/browser/ui/auto_login_infobar_delegate.h b/chrome/browser/ui/auto_login_infobar_delegate.h
index db47dae..f2481a2 100644
--- a/chrome/browser/ui/auto_login_infobar_delegate.h
+++ b/chrome/browser/ui/auto_login_infobar_delegate.h
@@ -58,8 +58,8 @@ class AutoLoginInfoBarDelegate : public ConfirmInfoBarDelegate,
   virtual int GetIconID() const OVERRIDE;
   virtual Type GetInfoBarType() const OVERRIDE;
   virtual AutoLoginInfoBarDelegate* AsAutoLoginInfoBarDelegate() OVERRIDE;
-  virtual string16 GetMessageText() const OVERRIDE;
-  virtual string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
   virtual bool Accept() OVERRIDE;
   virtual bool Cancel() OVERRIDE;
 
diff --git a/chrome/browser/ui/autofill/autofill_dialog_common.cc b/chrome/browser/ui/autofill/autofill_dialog_common.cc
index 753104e..0015896 100644
--- a/chrome/browser/ui/autofill/autofill_dialog_common.cc
+++ b/chrome/browser/ui/autofill/autofill_dialog_common.cc
@@ -213,7 +213,7 @@ string16 GetHardcodedValueForType(ServerFieldType type) {
     return country.name();
   }
 
-  return string16();
+  return base::string16();
 }
 
 }  // namespace common
diff --git a/chrome/browser/ui/autofill/autofill_dialog_controller_browsertest.cc b/chrome/browser/ui/autofill/autofill_dialog_controller_browsertest.cc
index e36e4f4..a6af2b0 100644
--- a/chrome/browser/ui/autofill/autofill_dialog_controller_browsertest.cc
+++ b/chrome/browser/ui/autofill/autofill_dialog_controller_browsertest.cc
@@ -123,12 +123,12 @@ class TestAutofillDialogController : public AutofillDialogControllerImpl {
     AutofillDialogControllerImpl::ViewClosed();
   }
 
-  virtual string16 InputValidityMessage(
+  virtual base::string16 InputValidityMessage(
       DialogSection section,
       ServerFieldType type,
-      const string16& value) OVERRIDE {
+      const base::string16& value) OVERRIDE {
     if (!use_validation_)
-      return string16();
+      return base::string16();
     return AutofillDialogControllerImpl::InputValidityMessage(
         section, type, value);
   }
@@ -505,7 +505,7 @@ IN_PROC_BROWSER_TEST_F(AutofillDialogControllerTest, FillInputFromAutofill) {
   const DetailInputs& inputs =
       controller()->RequestedFieldsForSection(SECTION_SHIPPING);
   const DetailInput& triggering_input = inputs[0];
-  string16 value = full_profile.GetRawInfo(triggering_input.type);
+  base::string16 value = full_profile.GetRawInfo(triggering_input.type);
   TestableAutofillDialogView* view = controller()->GetTestableView();
   view->SetTextContentsOfInput(triggering_input,
                                value.substr(0, value.size() / 2));
@@ -524,10 +524,11 @@ IN_PROC_BROWSER_TEST_F(AutofillDialogControllerTest, FillInputFromAutofill) {
   // Now simulate some user edits and try again.
   std::vector<string16> expectations;
   for (size_t i = 0; i < inputs.size(); ++i) {
-    string16 users_input = i % 2 == 0 ? string16() : ASCIIToUTF16("dummy");
+    base::string16 users_input = i % 2 == 0 ? base::string16()
+                                            : ASCIIToUTF16("dummy");
     view->SetTextContentsOfInput(inputs[i], users_input);
     // Empty inputs should be filled, others should be left alone.
-    string16 expectation =
+    base::string16 expectation =
         &inputs[i] == &triggering_input || users_input.empty() ?
         wrapper.GetInfo(AutofillType(inputs[i].type)) :
         users_input;
@@ -557,7 +558,7 @@ IN_PROC_BROWSER_TEST_F(AutofillDialogControllerTest,
   const DetailInputs& inputs =
       controller()->RequestedFieldsForSection(SECTION_SHIPPING);
   const DetailInput& triggering_input = inputs[0];
-  string16 value = full_profile.GetRawInfo(triggering_input.type);
+  base::string16 value = full_profile.GetRawInfo(triggering_input.type);
   TestableAutofillDialogView* view = controller()->GetTestableView();
   view->SetTextContentsOfInput(triggering_input,
                                value.substr(0, value.size() / 2));
@@ -569,7 +570,7 @@ IN_PROC_BROWSER_TEST_F(AutofillDialogControllerTest,
   // All inputs should be filled.
   AutofillProfileWrapper wrapper(&full_profile);
   for (size_t i = 0; i < inputs.size(); ++i) {
-    string16 expectation =
+    base::string16 expectation =
         AutofillType(inputs[i].type).GetStorableType() == ADDRESS_HOME_COUNTRY ?
         ASCIIToUTF16("United States") :
         wrapper.GetInfo(AutofillType(inputs[i].type));
@@ -579,10 +580,11 @@ IN_PROC_BROWSER_TEST_F(AutofillDialogControllerTest,
   // Now simulate some user edits and try again.
   std::vector<string16> expectations;
   for (size_t i = 0; i < inputs.size(); ++i) {
-    string16 users_input = i % 2 == 0 ? string16() : ASCIIToUTF16("dummy");
+    base::string16 users_input = i % 2 == 0 ? base::string16()
+                                            : ASCIIToUTF16("dummy");
     view->SetTextContentsOfInput(inputs[i], users_input);
     // Empty inputs should be filled, others should be left alone.
-    string16 expectation =
+    base::string16 expectation =
         &inputs[i] == &triggering_input || users_input.empty() ?
         wrapper.GetInfo(AutofillType(inputs[i].type)) :
         users_input;
@@ -669,7 +671,7 @@ IN_PROC_BROWSER_TEST_F(AutofillDialogControllerTest,
   const DetailInputs& inputs =
       controller()->RequestedFieldsForSection(SECTION_CC);
   const DetailInput& triggering_input = inputs[0];
-  string16 value = card1.GetRawInfo(triggering_input.type);
+  base::string16 value = card1.GetRawInfo(triggering_input.type);
   TestableAutofillDialogView* view = controller()->GetTestableView();
   view->SetTextContentsOfInput(triggering_input,
                                value.substr(0, value.size() / 2));
diff --git a/chrome/browser/ui/autofill/autofill_dialog_controller_impl.cc b/chrome/browser/ui/autofill/autofill_dialog_controller_impl.cc
index 127706e..f682dce 100644
--- a/chrome/browser/ui/autofill/autofill_dialog_controller_impl.cc
+++ b/chrome/browser/ui/autofill/autofill_dialog_controller_impl.cc
@@ -319,7 +319,7 @@ const wallet::Address* FindDuplicateAddress(
   return NULL;
 }
 
-bool IsCardHolderNameValidForWallet(const string16& name) {
+bool IsCardHolderNameValidForWallet(const base::string16& name) {
   base::string16 whitespace_collapsed_name = CollapseWhitespace(name, true);
   std::vector<base::string16> split_name;
   base::SplitString(whitespace_collapsed_name, ' ', &split_name);
@@ -660,14 +660,14 @@ TestableAutofillDialogView* AutofillDialogControllerImpl::GetTestableView() {
 ////////////////////////////////////////////////////////////////////////////////
 // AutofillDialogViewDelegate implementation.
 
-string16 AutofillDialogControllerImpl::DialogTitle() const {
+base::string16 AutofillDialogControllerImpl::DialogTitle() const {
   if (ShouldShowSpinner())
-    return string16();
+    return base::string16();
 
   return l10n_util::GetStringUTF16(IDS_AUTOFILL_DIALOG_TITLE);
 }
 
-string16 AutofillDialogControllerImpl::AccountChooserText() const {
+base::string16 AutofillDialogControllerImpl::AccountChooserText() const {
   if (!account_chooser_model_.WalletIsSelected())
     return l10n_util::GetStringUTF16(IDS_AUTOFILL_DIALOG_PAYING_WITHOUT_WALLET);
 
@@ -675,10 +675,10 @@ string16 AutofillDialogControllerImpl::AccountChooserText() const {
     return account_chooser_model_.GetActiveWalletAccountName();
 
   // In this case, the account chooser should be showing the signin link.
-  return string16();
+  return base::string16();
 }
 
-string16 AutofillDialogControllerImpl::SignInLinkText() const {
+base::string16 AutofillDialogControllerImpl::SignInLinkText() const {
   int ids = SignedInState() == NOT_CHECKED ?
       IDS_AUTOFILL_DIALOG_USE_WALLET_LINK :
       ShouldShowSignInWebView() ? IDS_AUTOFILL_DIALOG_CANCEL_SIGN_IN :
@@ -687,34 +687,34 @@ string16 AutofillDialogControllerImpl::SignInLinkText() const {
   return l10n_util::GetStringUTF16(ids);
 }
 
-string16 AutofillDialogControllerImpl::SpinnerText() const {
+base::string16 AutofillDialogControllerImpl::SpinnerText() const {
   return l10n_util::GetStringUTF16(IDS_AUTOFILL_DIALOG_LOADING);
 }
 
-string16 AutofillDialogControllerImpl::EditSuggestionText() const {
+base::string16 AutofillDialogControllerImpl::EditSuggestionText() const {
   return l10n_util::GetStringUTF16(IDS_AUTOFILL_DIALOG_EDIT);
 }
 
-string16 AutofillDialogControllerImpl::CancelButtonText() const {
+base::string16 AutofillDialogControllerImpl::CancelButtonText() const {
   return l10n_util::GetStringUTF16(IDS_CANCEL);
 }
 
-string16 AutofillDialogControllerImpl::ConfirmButtonText() const {
+base::string16 AutofillDialogControllerImpl::ConfirmButtonText() const {
   return l10n_util::GetStringUTF16(IsSubmitPausedOn(wallet::VERIFY_CVV) ?
       IDS_AUTOFILL_DIALOG_VERIFY_BUTTON : IDS_AUTOFILL_DIALOG_SUBMIT_BUTTON);
 }
 
-string16 AutofillDialogControllerImpl::SaveLocallyText() const {
+base::string16 AutofillDialogControllerImpl::SaveLocallyText() const {
   return l10n_util::GetStringUTF16(IDS_AUTOFILL_DIALOG_SAVE_LOCALLY_CHECKBOX);
 }
 
-string16 AutofillDialogControllerImpl::SaveLocallyTooltip() const {
+base::string16 AutofillDialogControllerImpl::SaveLocallyTooltip() const {
   return l10n_util::GetStringUTF16(IDS_AUTOFILL_DIALOG_SAVE_LOCALLY_TOOLTIP);
 }
 
-string16 AutofillDialogControllerImpl::LegalDocumentsText() {
+base::string16 AutofillDialogControllerImpl::LegalDocumentsText() {
   if (!IsPayingWithWallet() || ShouldShowSignInWebView())
-    return string16();
+    return base::string16();
 
   return legal_documents_text_;
 }
@@ -795,7 +795,7 @@ DialogOverlayState AutofillDialogControllerImpl::GetDialogOverlay() {
     card_scrambling_delay_.Stop();
     card_scrambling_refresher_.Stop();
 
-    string16 cc_number =
+    base::string16 cc_number =
         full_wallet_->GetInfo(AutofillType(CREDIT_CARD_NUMBER));
     DCHECK_GE(cc_number.size(), 4U);
     state.image = GetGeneratedCardImage(
@@ -1070,7 +1070,8 @@ void AutofillDialogControllerImpl::ConstructLegalDocumentsText() {
   }
 
   std::vector<size_t> offsets;
-  string16 text = l10n_util::GetStringFUTF16(resource_id, link_names, &offsets);
+  base::string16 text =
+      l10n_util::GetStringFUTF16(resource_id, link_names,&offsets);
 
   // Tack on the location string if need be.
   size_t base_offset = 0;
@@ -1107,7 +1108,7 @@ void AutofillDialogControllerImpl::ShowEditUiIfBadSuggestion(
   // If the chosen item in |model| yields an empty suggestion text, it is
   // invalid. In this case, show the edit UI and highlight invalid fields.
   SuggestionsMenuModel* model = SuggestionsMenuModelForSection(section);
-  string16 unused, unused2;
+  base::string16 unused, unused2;
   if (IsASuggestionItemKey(model->GetItemKeyForCheckedItem()) &&
       !SuggestionTextForSection(section, &unused, &unused2)) {
     SetEditingExistingData(section, true);
@@ -1355,8 +1356,8 @@ gfx::Image AutofillDialogControllerImpl::ButtonStripImage() const {
   return gfx::Image();
 }
 
-string16 AutofillDialogControllerImpl::LabelForSection(DialogSection section)
-    const {
+base::string16 AutofillDialogControllerImpl::LabelForSection(
+    DialogSection section) const {
   switch (section) {
     case SECTION_CC:
       return l10n_util::GetStringUTF16(IDS_AUTOFILL_DIALOG_SECTION_CC);
@@ -1367,12 +1368,12 @@ string16 AutofillDialogControllerImpl::LabelForSection(DialogSection section)
       return l10n_util::GetStringUTF16(IDS_AUTOFILL_DIALOG_SECTION_SHIPPING);
   }
   NOTREACHED();
-  return string16();
+  return base::string16();
 }
 
 SuggestionState AutofillDialogControllerImpl::SuggestionStateForSection(
     DialogSection section) {
-  string16 vertically_compact, horizontally_compact;
+  base::string16 vertically_compact, horizontally_compact;
   bool show_suggestion = SuggestionTextForSection(section,
                                                   &vertically_compact,
                                                   &horizontally_compact);
@@ -1415,7 +1416,7 @@ bool AutofillDialogControllerImpl::SuggestionTextForSection(
   return wrapper->GetDisplayText(vertically_compact, horizontally_compact);
 }
 
-string16 AutofillDialogControllerImpl::RequiredActionTextForSection(
+base::string16 AutofillDialogControllerImpl::RequiredActionTextForSection(
     DialogSection section) const {
   if (section == SECTION_CC_BILLING && IsSubmitPausedOn(wallet::VERIFY_CVV)) {
     const wallet::WalletItems::MaskedInstrument* current_instrument =
@@ -1430,17 +1431,17 @@ string16 AutofillDialogControllerImpl::RequiredActionTextForSection(
     return card.TypeAndLastFourDigits();
   }
 
-  return string16();
+  return base::string16();
 }
 
-string16 AutofillDialogControllerImpl::ExtraSuggestionTextForSection(
+base::string16 AutofillDialogControllerImpl::ExtraSuggestionTextForSection(
     DialogSection section) const {
   if (section == SECTION_CC ||
       (section == SECTION_CC_BILLING && IsSubmitPausedOn(wallet::VERIFY_CVV))) {
     return l10n_util::GetStringUTF16(IDS_AUTOFILL_DIALOG_PLACEHOLDER_CVC);
   }
 
-  return string16();
+  return base::string16();
 }
 
 const wallet::WalletItems::MaskedInstrument* AutofillDialogControllerImpl::
@@ -1565,7 +1566,7 @@ FieldIconMap AutofillDialogControllerImpl::IconsForFields(
   FieldValueMap::const_iterator credit_card_iter =
       user_inputs.find(CREDIT_CARD_NUMBER);
   if (credit_card_iter != user_inputs.end()) {
-    const string16& number = credit_card_iter->second;
+    const base::string16& number = credit_card_iter->second;
     const std::string type = CreditCard::GetCreditCardType(number);
     credit_card_type = CreditCard::TypeForDisplay(type);
     result[CREDIT_CARD_NUMBER] = CreditCardIconForType(type);
@@ -1585,12 +1586,12 @@ bool AutofillDialogControllerImpl::FieldControlsIcons(
   return type == CREDIT_CARD_NUMBER;
 }
 
-string16 AutofillDialogControllerImpl::TooltipForField(ServerFieldType type)
-    const {
+base::string16 AutofillDialogControllerImpl::TooltipForField(
+    ServerFieldType type) const {
   if (type == PHONE_HOME_WHOLE_NUMBER || type == PHONE_BILLING_WHOLE_NUMBER)
     return l10n_util::GetStringUTF16(IDS_AUTOFILL_DIALOG_TOOLTIP_PHONE_NUMBER);
 
-  return string16();
+  return base::string16();
 }
 
 bool AutofillDialogControllerImpl::InputIsEditable(
@@ -1629,10 +1630,10 @@ bool AutofillDialogControllerImpl::InputIsEditable(
 }
 
 // TODO(groby): Add more tests.
-string16 AutofillDialogControllerImpl::InputValidityMessage(
+base::string16 AutofillDialogControllerImpl::InputValidityMessage(
     DialogSection section,
     ServerFieldType type,
-    const string16& value) {
+    const base::string16& value) {
   // If the field is edited, clear any Wallet errors.
   if (IsPayingWithWallet()) {
     WalletValidationErrors::iterator it = wallet_errors_.find(section);
@@ -1739,7 +1740,7 @@ ValidityMessages AutofillDialogControllerImpl::InputsAreValid(
     DialogSection section,
     const FieldValueMap& inputs) {
   ValidityMessages messages;
-  std::map<ServerFieldType, string16> field_values;
+  std::map<ServerFieldType, base::string16> field_values;
   for (FieldValueMap::const_iterator iter = inputs.begin();
        iter != inputs.end(); ++iter) {
     const ServerFieldType type = iter->first;
@@ -1843,7 +1844,7 @@ void AutofillDialogControllerImpl::UserEditedOrActivatedInput(
     ServerFieldType type,
     gfx::NativeView parent_view,
     const gfx::Rect& content_bounds,
-    const string16& field_contents,
+    const base::string16& field_contents,
     bool was_edit) {
   // If the field is edited down to empty, don't show a popup.
   if (was_edit && field_contents.empty()) {
@@ -2146,8 +2147,9 @@ void AutofillDialogControllerImpl::DidSelectSuggestion(int identifier) {
   // TODO(estade): implement.
 }
 
-void AutofillDialogControllerImpl::DidAcceptSuggestion(const string16& value,
-                                                       int identifier) {
+void AutofillDialogControllerImpl::DidAcceptSuggestion(
+    const base::string16& value,
+    int identifier) {
   ScopedViewUpdates updates(view_.get());
   const PersonalDataManager::GUIDPair& pair = popup_guids_[identifier];
 
@@ -2175,8 +2177,9 @@ void AutofillDialogControllerImpl::DidAcceptSuggestion(const string16& value,
   HidePopup();
 }
 
-void AutofillDialogControllerImpl::RemoveSuggestion(const string16& value,
-                                                    int identifier) {
+void AutofillDialogControllerImpl::RemoveSuggestion(
+    const base::string16& value,
+    int identifier) {
   // TODO(estade): implement.
 }
 
@@ -2943,7 +2946,7 @@ void AutofillDialogControllerImpl::SetOutputForFieldsOfType(
   }
 }
 
-string16 AutofillDialogControllerImpl::GetValueFromSection(
+base::string16 AutofillDialogControllerImpl::GetValueFromSection(
     DialogSection section,
     ServerFieldType type) {
   DCHECK(SectionIsActive(section));
@@ -3218,7 +3221,7 @@ scoped_ptr<wallet::Instrument> AutofillDialogControllerImpl::
 
   CreditCard card;
   AutofillProfile profile;
-  string16 cvc;
+  base::string16 cvc;
   GetBillingInfoFromOutputs(output, &card, &cvc, &profile);
 
   return scoped_ptr<wallet::Instrument>(
diff --git a/chrome/browser/ui/autofill/autofill_dialog_controller_impl.h b/chrome/browser/ui/autofill/autofill_dialog_controller_impl.h
index a9acd42..b5556ec 100644
--- a/chrome/browser/ui/autofill/autofill_dialog_controller_impl.h
+++ b/chrome/browser/ui/autofill/autofill_dialog_controller_impl.h
@@ -96,16 +96,16 @@ class AutofillDialogControllerImpl : public AutofillDialogViewDelegate,
   TestableAutofillDialogView* GetTestableView();
 
   // AutofillDialogViewDelegate implementation.
-  virtual string16 DialogTitle() const OVERRIDE;
-  virtual string16 AccountChooserText() const OVERRIDE;
-  virtual string16 SignInLinkText() const OVERRIDE;
-  virtual string16 SpinnerText() const OVERRIDE;
-  virtual string16 EditSuggestionText() const OVERRIDE;
-  virtual string16 CancelButtonText() const OVERRIDE;
-  virtual string16 ConfirmButtonText() const OVERRIDE;
-  virtual string16 SaveLocallyText() const OVERRIDE;
-  virtual string16 SaveLocallyTooltip() const OVERRIDE;
-  virtual string16 LegalDocumentsText() OVERRIDE;
+  virtual base::string16 DialogTitle() const OVERRIDE;
+  virtual base::string16 AccountChooserText() const OVERRIDE;
+  virtual base::string16 SignInLinkText() const OVERRIDE;
+  virtual base::string16 SpinnerText() const OVERRIDE;
+  virtual base::string16 EditSuggestionText() const OVERRIDE;
+  virtual base::string16 CancelButtonText() const OVERRIDE;
+  virtual base::string16 ConfirmButtonText() const OVERRIDE;
+  virtual base::string16 SaveLocallyText() const OVERRIDE;
+  virtual base::string16 SaveLocallyTooltip() const OVERRIDE;
+  virtual base::string16 LegalDocumentsText() OVERRIDE;
   virtual bool ShouldShowSpinner() const OVERRIDE;
   virtual bool ShouldShowSignInWebView() const OVERRIDE;
   virtual GURL SignInUrl() const OVERRIDE;
@@ -124,25 +124,25 @@ class AutofillDialogControllerImpl : public AutofillDialogViewDelegate,
   virtual ui::ComboboxModel* ComboboxModelForAutofillType(
       ServerFieldType type) OVERRIDE;
   virtual ui::MenuModel* MenuModelForSection(DialogSection section) OVERRIDE;
-  virtual string16 LabelForSection(DialogSection section) const OVERRIDE;
+  virtual base::string16 LabelForSection(DialogSection section) const OVERRIDE;
   virtual SuggestionState SuggestionStateForSection(
       DialogSection section) OVERRIDE;
   virtual FieldIconMap IconsForFields(const FieldValueMap& user_inputs)
       const OVERRIDE;
   virtual bool FieldControlsIcons(ServerFieldType type) const OVERRIDE;
-  virtual string16 TooltipForField(ServerFieldType type) const OVERRIDE;
+  virtual base::string16 TooltipForField(ServerFieldType type) const OVERRIDE;
   virtual bool InputIsEditable(const DetailInput& input, DialogSection section)
       OVERRIDE;
-  virtual string16 InputValidityMessage(DialogSection section,
+  virtual base::string16 InputValidityMessage(DialogSection section,
                                         ServerFieldType type,
-                                        const string16& value) OVERRIDE;
+                                        const base::string16& value) OVERRIDE;
   virtual ValidityMessages InputsAreValid(
       DialogSection section, const FieldValueMap& inputs) OVERRIDE;
   virtual void UserEditedOrActivatedInput(DialogSection section,
                                           ServerFieldType type,
                                           gfx::NativeView parent_view,
                                           const gfx::Rect& content_bounds,
-                                          const string16& field_contents,
+                                          const base::string16& field_contents,
                                           bool was_edit) OVERRIDE;
   virtual bool HandleKeyPressEventInInput(
       const content::NativeWebKeyboardEvent& event) OVERRIDE;
@@ -165,9 +165,9 @@ class AutofillDialogControllerImpl : public AutofillDialogViewDelegate,
   virtual void OnPopupHidden() OVERRIDE;
   virtual bool ShouldRepostEvent(const ui::MouseEvent& event) OVERRIDE;
   virtual void DidSelectSuggestion(int identifier) OVERRIDE;
-  virtual void DidAcceptSuggestion(const string16& value,
+  virtual void DidAcceptSuggestion(const base::string16& value,
                                    int identifier) OVERRIDE;
-  virtual void RemoveSuggestion(const string16& value,
+  virtual void RemoveSuggestion(const base::string16& value,
                                 int identifier) OVERRIDE;
   virtual void ClearPreviewedForm() OVERRIDE;
 
@@ -412,11 +412,12 @@ class AutofillDialogControllerImpl : public AutofillDialogViewDelegate,
 
   // Finds all fields of the given |type| in |form_structure_|, if any, and sets
   // each field's value to |output|.
-  void SetOutputForFieldsOfType(ServerFieldType type, const string16& output);
+  void SetOutputForFieldsOfType(ServerFieldType type,
+                                const base::string16& output);
 
   // Gets the value for |type| in |section|, whether it comes from manual user
   // input or the active suggestion.
-  string16 GetValueFromSection(DialogSection section,
+  base::string16 GetValueFromSection(DialogSection section,
                                ServerFieldType type);
 
   // Gets the SuggestionsMenuModel for |section|.
@@ -434,9 +435,9 @@ class AutofillDialogControllerImpl : public AutofillDialogViewDelegate,
   bool SuggestionTextForSection(DialogSection section,
                                 base::string16* vertically_compact,
                                 base::string16* horizontally_compact);
-  string16 RequiredActionTextForSection(DialogSection section) const;
+  base::string16 RequiredActionTextForSection(DialogSection section) const;
   gfx::Image SuggestionIconForSection(DialogSection section);
-  string16 ExtraSuggestionTextForSection(DialogSection section) const;
+  base::string16 ExtraSuggestionTextForSection(DialogSection section) const;
   gfx::Image ExtraSuggestionIconForSection(DialogSection section);
 
   // Loads profiles that can suggest data for |type|. |field_contents| is the
@@ -445,7 +446,7 @@ class AutofillDialogControllerImpl : public AutofillDialogViewDelegate,
   // |popup_guids_|.
   void GetProfileSuggestions(
       ServerFieldType type,
-      const string16& field_contents,
+      const base::string16& field_contents,
       const DetailInputs& inputs,
       std::vector<string16>* popup_values,
       std::vector<string16>* popup_labels,
@@ -635,7 +636,7 @@ class AutofillDialogControllerImpl : public AutofillDialogViewDelegate,
   std::string risk_data_;
 
   // The text to display when the user is accepting new terms of service, etc.
-  string16 legal_documents_text_;
+  base::string16 legal_documents_text_;
   // The ranges within |legal_documents_text_| to linkify.
   std::vector<gfx::Range> legal_document_link_ranges_;
 
diff --git a/chrome/browser/ui/autofill/autofill_dialog_controller_unittest.cc b/chrome/browser/ui/autofill/autofill_dialog_controller_unittest.cc
index bb5be6d4..70fb6fc 100644
--- a/chrome/browser/ui/autofill/autofill_dialog_controller_unittest.cc
+++ b/chrome/browser/ui/autofill/autofill_dialog_controller_unittest.cc
@@ -180,7 +180,7 @@ class TestAutofillDialogView : public AutofillDialogView {
     return NULL;
   }
 
-  virtual string16 GetCvc() OVERRIDE { return string16(); }
+  virtual base::string16 GetCvc() OVERRIDE { return base::string16(); }
   virtual bool HitTestInput(const DetailInput& input,
                             const gfx::Point& screen_point) OVERRIDE {
     return false;
@@ -623,7 +623,7 @@ TEST_F(AutofillDialogControllerTest, ValidityCheck) {
         controller()->RequestedFieldsForSection(section);
     for (DetailInputs::const_iterator iter = shipping_inputs.begin();
          iter != shipping_inputs.end(); ++iter) {
-      controller()->InputValidityMessage(section, iter->type, string16());
+      controller()->InputValidityMessage(section, iter->type, base::string16());
     }
   }
 }
@@ -849,7 +849,7 @@ TEST_F(AutofillDialogControllerTest, AutofillProfiles) {
   // An otherwise full but unverified profile should be ignored.
   AutofillProfile full_profile(test::GetFullProfile());
   full_profile.set_origin("https://www.example.com");
-  full_profile.SetRawInfo(ADDRESS_HOME_LINE2, string16());
+  full_profile.SetRawInfo(ADDRESS_HOME_LINE2, base::string16());
   controller()->GetTestingManager()->AddTestingProfile(&full_profile);
   shipping_model = controller()->MenuModelForSection(SECTION_SHIPPING);
   ASSERT_TRUE(shipping_model);
@@ -857,7 +857,7 @@ TEST_F(AutofillDialogControllerTest, AutofillProfiles) {
 
   // A full, verified profile should be picked up.
   AutofillProfile verified_profile(test::GetVerifiedProfile());
-  verified_profile.SetRawInfo(ADDRESS_HOME_LINE2, string16());
+  verified_profile.SetRawInfo(ADDRESS_HOME_LINE2, base::string16());
   controller()->GetTestingManager()->AddTestingProfile(&verified_profile);
   shipping_model = controller()->MenuModelForSection(SECTION_SHIPPING);
   ASSERT_TRUE(shipping_model);
@@ -973,7 +973,7 @@ TEST_F(AutofillDialogControllerTest, AutofillProfileVariants) {
 TEST_F(AutofillDialogControllerTest, SuggestValidEmail) {
   SwitchToAutofill();
   AutofillProfile profile(test::GetVerifiedProfile());
-  const string16 kValidEmail = ASCIIToUTF16(kFakeEmail);
+  const base::string16 kValidEmail = ASCIIToUTF16(kFakeEmail);
   profile.SetRawInfo(EMAIL_ADDRESS, kValidEmail);
   controller()->GetTestingManager()->AddTestingProfile(&profile);
 
@@ -1077,21 +1077,21 @@ TEST_F(AutofillDialogControllerTest, DontUseBillingAsShipping) {
   EXPECT_EQ(ADDRESS_HOME_STATE,
             form_structure()->field(16)->Type().GetStorableType());
   EXPECT_EQ(ADDRESS_HOME, form_structure()->field(16)->Type().group());
-  string16 billing_state = form_structure()->field(9)->value;
-  string16 shipping_state = form_structure()->field(16)->value;
+  base::string16 billing_state = form_structure()->field(9)->value;
+  base::string16 shipping_state = form_structure()->field(16)->value;
   EXPECT_FALSE(billing_state.empty());
   EXPECT_FALSE(shipping_state.empty());
   EXPECT_NE(billing_state, shipping_state);
 
   EXPECT_EQ(CREDIT_CARD_NAME,
             form_structure()->field(1)->Type().GetStorableType());
-  string16 cc_name = form_structure()->field(1)->value;
+  base::string16 cc_name = form_structure()->field(1)->value;
   EXPECT_EQ(NAME_FULL, form_structure()->field(6)->Type().GetStorableType());
   EXPECT_EQ(NAME_BILLING, form_structure()->field(6)->Type().group());
-  string16 billing_name = form_structure()->field(6)->value;
+  base::string16 billing_name = form_structure()->field(6)->value;
   EXPECT_EQ(NAME_FULL, form_structure()->field(13)->Type().GetStorableType());
   EXPECT_EQ(NAME, form_structure()->field(13)->Type().group());
-  string16 shipping_name = form_structure()->field(13)->value;
+  base::string16 shipping_name = form_structure()->field(13)->value;
 
   EXPECT_FALSE(cc_name.empty());
   EXPECT_FALSE(billing_name.empty());
@@ -1122,21 +1122,21 @@ TEST_F(AutofillDialogControllerTest, UseBillingAsShipping) {
   EXPECT_EQ(ADDRESS_HOME_STATE,
             form_structure()->field(16)->Type().GetStorableType());
   EXPECT_EQ(ADDRESS_HOME, form_structure()->field(16)->Type().group());
-  string16 billing_state = form_structure()->field(9)->value;
-  string16 shipping_state = form_structure()->field(16)->value;
+  base::string16 billing_state = form_structure()->field(9)->value;
+  base::string16 shipping_state = form_structure()->field(16)->value;
   EXPECT_FALSE(billing_state.empty());
   EXPECT_FALSE(shipping_state.empty());
   EXPECT_EQ(billing_state, shipping_state);
 
   EXPECT_EQ(CREDIT_CARD_NAME,
             form_structure()->field(1)->Type().GetStorableType());
-  string16 cc_name = form_structure()->field(1)->value;
+  base::string16 cc_name = form_structure()->field(1)->value;
   EXPECT_EQ(NAME_FULL, form_structure()->field(6)->Type().GetStorableType());
   EXPECT_EQ(NAME_BILLING, form_structure()->field(6)->Type().group());
-  string16 billing_name = form_structure()->field(6)->value;
+  base::string16 billing_name = form_structure()->field(6)->value;
   EXPECT_EQ(NAME_FULL, form_structure()->field(13)->Type().GetStorableType());
   EXPECT_EQ(NAME, form_structure()->field(13)->Type().group());
-  string16 shipping_name = form_structure()->field(13)->value;
+  base::string16 shipping_name = form_structure()->field(13)->value;
 
   EXPECT_FALSE(cc_name.empty());
   EXPECT_FALSE(billing_name.empty());
@@ -1589,7 +1589,7 @@ TEST_F(AutofillDialogControllerTest, CancelNoSave) {
 TEST_F(AutofillDialogControllerTest, ManageItem) {
   AutofillProfile full_profile(test::GetVerifiedProfile());
   full_profile.set_origin(kSettingsOrigin);
-  full_profile.SetRawInfo(ADDRESS_HOME_LINE2, string16());
+  full_profile.SetRawInfo(ADDRESS_HOME_LINE2, base::string16());
   controller()->GetTestingManager()->AddTestingProfile(&full_profile);
   SwitchToAutofill();
 
diff --git a/chrome/browser/ui/autofill/autofill_dialog_models.cc b/chrome/browser/ui/autofill/autofill_dialog_models.cc
index 791835a..1eae057 100644
--- a/chrome/browser/ui/autofill/autofill_dialog_models.cc
+++ b/chrome/browser/ui/autofill/autofill_dialog_models.cc
@@ -32,7 +32,7 @@ SuggestionsMenuModel::SuggestionsMenuModel(
 SuggestionsMenuModel::~SuggestionsMenuModel() {}
 
 void SuggestionsMenuModel::AddKeyedItem(
-    const std::string& key, const string16& display_label) {
+    const std::string& key, const base::string16& display_label) {
   Item item = { key, true };
   items_.push_back(item);
   AddCheckItem(items_.size() - 1, display_label);
@@ -40,7 +40,7 @@ void SuggestionsMenuModel::AddKeyedItem(
 
 void SuggestionsMenuModel::AddKeyedItemWithIcon(
     const std::string& key,
-    const string16& display_label,
+    const base::string16& display_label,
     const gfx::Image& icon) {
   AddKeyedItem(key, display_label);
   SetIcon(items_.size() - 1, icon);
@@ -48,16 +48,16 @@ void SuggestionsMenuModel::AddKeyedItemWithIcon(
 
 void SuggestionsMenuModel::AddKeyedItemWithMinorText(
     const std::string& key,
-    const string16& display_label,
-    const string16& display_minor_text) {
+    const base::string16& display_label,
+    const base::string16& display_minor_text) {
   AddKeyedItem(key, display_label);
   SetMinorText(items_.size() - 1, display_minor_text);
 }
 
 void SuggestionsMenuModel::AddKeyedItemWithMinorTextAndIcon(
     const std::string& key,
-    const string16& display_label,
-    const string16& display_minor_text,
+    const base::string16& display_label,
+    const base::string16& display_minor_text,
     const gfx::Image& icon) {
   AddKeyedItemWithIcon(key, display_label, icon);
   SetMinorText(items_.size() - 1, display_minor_text);
diff --git a/chrome/browser/ui/autofill/autofill_dialog_models.h b/chrome/browser/ui/autofill/autofill_dialog_models.h
index de62b45..0986559 100644
--- a/chrome/browser/ui/autofill/autofill_dialog_models.h
+++ b/chrome/browser/ui/autofill/autofill_dialog_models.h
@@ -40,26 +40,28 @@ class SuggestionsMenuModel : public ui::SimpleMenuModel,
   virtual ~SuggestionsMenuModel();
 
   // Adds an item and its identifying key to the model. Keys needn't be unique.
-  void AddKeyedItem(const std::string& key, const string16& display_label);
+  void AddKeyedItem(const std::string& key,
+                    const base::string16& display_label);
 
   // As above, but also accepts an image which will be displayed alongside the
   // text.
   void AddKeyedItemWithIcon(const std::string& key,
-                            const string16& display_label,
+                            const base::string16& display_label,
                             const gfx::Image& icon);
 
   // Adds a label with a minor text and its identifying key to the model.
   // Keys needn't be unique.
   void AddKeyedItemWithMinorText(const std::string& key,
-                                const string16& display_label,
-                                const string16& display_minor_text);
+                                const base::string16& display_label,
+                                const base::string16& display_minor_text);
 
   // As above, but also accepts an image which will be displayed alongside the
   // text.
-  void AddKeyedItemWithMinorTextAndIcon(const std::string& key,
-                                        const string16& display_label,
-                                        const string16& display_minor_text,
-                                        const gfx::Image& icon);
+  void AddKeyedItemWithMinorTextAndIcon(
+      const std::string& key,
+      const base::string16& display_label,
+      const base::string16& display_minor_text,
+      const gfx::Image& icon);
 
   // Resets the model to empty.
   void Reset();
@@ -120,11 +122,11 @@ class MonthComboboxModel : public ui::ComboboxModel {
   MonthComboboxModel();
   virtual ~MonthComboboxModel();
 
-  static string16 FormatMonth(int index);
+  static base::string16 FormatMonth(int index);
 
   // ui::Combobox implementation:
   virtual int GetItemCount() const OVERRIDE;
-  virtual string16 GetItemAt(int index) OVERRIDE;
+  virtual base::string16 GetItemAt(int index) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MonthComboboxModel);
@@ -138,7 +140,7 @@ class YearComboboxModel : public ui::ComboboxModel {
 
   // ui::Combobox implementation:
   virtual int GetItemCount() const OVERRIDE;
-  virtual string16 GetItemAt(int index) OVERRIDE;
+  virtual base::string16 GetItemAt(int index) OVERRIDE;
 
  private:
   // The current year (e.g., 2012).
diff --git a/chrome/browser/ui/autofill/autofill_dialog_types.cc b/chrome/browser/ui/autofill/autofill_dialog_types.cc
index 1225f3b..f6d6b07 100644
--- a/chrome/browser/ui/autofill/autofill_dialog_types.cc
+++ b/chrome/browser/ui/autofill/autofill_dialog_types.cc
@@ -25,7 +25,8 @@ static const base::char16 kRangeSeparator = '|';
 
 DialogNotification::DialogNotification() : type_(NONE) {}
 
-DialogNotification::DialogNotification(Type type, const string16& display_text)
+DialogNotification::DialogNotification(Type type,
+                                       const base::string16& display_text)
     : type_(type),
       display_text_(display_text),
       checked_(false) {
@@ -36,7 +37,7 @@ DialogNotification::DialogNotification(Type type, const string16& display_text)
     size_t start = pieces[0].size();
     size_t end = start + pieces[1].size();
     link_range_ = gfx::Range(start, end);
-    display_text_ = JoinString(pieces, string16());
+    display_text_ = JoinString(pieces, base::string16());
   }
 }
 
@@ -106,12 +107,13 @@ SkColor const kWarningColor = SkColorSetRGB(0xde, 0x49, 0x32);
 
 SuggestionState::SuggestionState()
     : visible(false) {}
-SuggestionState::SuggestionState(bool visible,
-                                 const string16& vertically_compact_text,
-                                 const string16& horizontally_compact_text,
-                                 const gfx::Image& icon,
-                                 const string16& extra_text,
-                                 const gfx::Image& extra_icon)
+SuggestionState::SuggestionState(
+    bool visible,
+    const base::string16& vertically_compact_text,
+    const base::string16& horizontally_compact_text,
+    const gfx::Image& icon,
+    const base::string16& extra_text,
+    const gfx::Image& extra_icon)
     : visible(visible),
       vertically_compact_text(vertically_compact_text),
       horizontally_compact_text(horizontally_compact_text),
diff --git a/chrome/browser/ui/autofill/autofill_dialog_view.h b/chrome/browser/ui/autofill/autofill_dialog_view.h
index 04ccd24..39ab3be 100644
--- a/chrome/browser/ui/autofill/autofill_dialog_view.h
+++ b/chrome/browser/ui/autofill/autofill_dialog_view.h
@@ -79,7 +79,7 @@ class AutofillDialogView {
   // Gets the CVC value the user typed to go along with the stored credit card
   // data. If the user is inputing credit card data from scratch, this is not
   // relevant.
-  virtual string16 GetCvc() = 0;
+  virtual base::string16 GetCvc() = 0;
 
   // Whether or not |point| is within |input|'s bounds.
   virtual bool HitTestInput(const DetailInput& input,
diff --git a/chrome/browser/ui/autofill/autofill_dialog_view_delegate.h b/chrome/browser/ui/autofill/autofill_dialog_view_delegate.h
index 1f035a9..bc1053b 100644
--- a/chrome/browser/ui/autofill/autofill_dialog_view_delegate.h
+++ b/chrome/browser/ui/autofill/autofill_dialog_view_delegate.h
@@ -43,16 +43,16 @@ class AutofillDialogViewDelegate {
  public:
   // Strings -------------------------------------------------------------------
 
-  virtual string16 DialogTitle() const = 0;
-  virtual string16 AccountChooserText() const = 0;
-  virtual string16 SignInLinkText() const = 0;
-  virtual string16 SpinnerText() const = 0;
-  virtual string16 EditSuggestionText() const = 0;
-  virtual string16 CancelButtonText() const = 0;
-  virtual string16 ConfirmButtonText() const = 0;
-  virtual string16 SaveLocallyText() const = 0;
-  virtual string16 SaveLocallyTooltip() const = 0;
-  virtual string16 LegalDocumentsText() = 0;
+  virtual base::string16 DialogTitle() const = 0;
+  virtual base::string16 AccountChooserText() const = 0;
+  virtual base::string16 SignInLinkText() const = 0;
+  virtual base::string16 SpinnerText() const = 0;
+  virtual base::string16 EditSuggestionText() const = 0;
+  virtual base::string16 CancelButtonText() const = 0;
+  virtual base::string16 ConfirmButtonText() const = 0;
+  virtual base::string16 SaveLocallyText() const = 0;
+  virtual base::string16 SaveLocallyTooltip() const = 0;
+  virtual base::string16 LegalDocumentsText() = 0;
 
   // State ---------------------------------------------------------------------
 
@@ -118,7 +118,7 @@ class AutofillDialogViewDelegate {
   virtual ui::MenuModel* MenuModelForSection(DialogSection section) = 0;
 
   // Returns the label text used to describe the section (i.e. Billing).
-  virtual string16 LabelForSection(DialogSection section) const = 0;
+  virtual base::string16 LabelForSection(DialogSection section) const = 0;
 
   // Returns the current state of suggestions for |section|.
   virtual SuggestionState SuggestionStateForSection(DialogSection section) = 0;
@@ -133,7 +133,7 @@ class AutofillDialogViewDelegate {
   virtual bool FieldControlsIcons(ServerFieldType type) const = 0;
 
   // Returns a tooltip for the given field, or an empty string if none exists.
-  virtual string16 TooltipForField(ServerFieldType type) const = 0;
+  virtual base::string16 TooltipForField(ServerFieldType type) const = 0;
 
   // Whether a particular DetailInput in |section| should be edited or not.
   virtual bool InputIsEditable(const DetailInput& input,
@@ -142,9 +142,9 @@ class AutofillDialogViewDelegate {
   // Decides whether input of |value| is valid for a field of type |type|. If
   // valid, the returned string will be empty. Otherwise it will contain an
   // error message.
-  virtual string16 InputValidityMessage(DialogSection section,
+  virtual base::string16 InputValidityMessage(DialogSection section,
                                         ServerFieldType type,
-                                        const string16& value) = 0;
+                                        const base::string16& value) = 0;
 
 
   // Decides whether the combination of all |inputs| is valid, returns a
@@ -159,7 +159,7 @@ class AutofillDialogViewDelegate {
                                           ServerFieldType type,
                                           gfx::NativeView parent_view,
                                           const gfx::Rect& content_bounds,
-                                          const string16& field_contents,
+                                          const base::string16& field_contents,
                                           bool was_edit) = 0;
 
   // The view forwards keypresses in text inputs. Returns true if there should
diff --git a/chrome/browser/ui/autofill/autofill_popup_controller.h b/chrome/browser/ui/autofill/autofill_popup_controller.h
index d35cf89..e9f6851 100644
--- a/chrome/browser/ui/autofill/autofill_popup_controller.h
+++ b/chrome/browser/ui/autofill/autofill_popup_controller.h
@@ -56,7 +56,7 @@ class AutofillPopupController {
 
   // Gets the resource value for the given resource, returning -1 if the
   // resource isn't recognized.
-  virtual int GetIconResourceID(const string16& resource_name) const = 0;
+  virtual int GetIconResourceID(const base::string16& resource_name) const = 0;
 
   // Returns true if the given index refers to an element that can be deleted.
   virtual bool CanDelete(size_t index) const = 0;
diff --git a/chrome/browser/ui/autofill/autofill_popup_controller_impl.cc b/chrome/browser/ui/autofill/autofill_popup_controller_impl.cc
index b42617c..77b6447 100644
--- a/chrome/browser/ui/autofill/autofill_popup_controller_impl.cc
+++ b/chrome/browser/ui/autofill/autofill_popup_controller_impl.cc
@@ -226,9 +226,9 @@ void AutofillPopupControllerImpl::UpdateDataListValues(
   // Add a separator if there are any other values.
   if (!identifiers_.empty() &&
       identifiers_[0] != WebAutofillClient::MenuItemIDSeparator) {
-    names_.insert(names_.begin(), string16());
-    subtexts_.insert(subtexts_.begin(), string16());
-    icons_.insert(icons_.begin(), string16());
+    names_.insert(names_.begin(), base::string16());
+    subtexts_.insert(subtexts_.begin(), base::string16());
+    icons_.insert(icons_.begin(), base::string16());
     identifiers_.insert(identifiers_.begin(),
                         WebAutofillClient::MenuItemIDSeparator);
   }
@@ -340,7 +340,7 @@ void AutofillPopupControllerImpl::AcceptSuggestion(size_t index) {
 }
 
 int AutofillPopupControllerImpl::GetIconResourceID(
-    const string16& resource_name) const {
+    const base::string16& resource_name) const {
   for (size_t i = 0; i < arraysize(kDataResources); ++i) {
     if (resource_name == ASCIIToUTF16(kDataResources[i].name))
       return kDataResources[i].id;
diff --git a/chrome/browser/ui/autofill/autofill_popup_controller_impl.h b/chrome/browser/ui/autofill/autofill_popup_controller_impl.h
index e1891c5..25dc09a 100644
--- a/chrome/browser/ui/autofill/autofill_popup_controller_impl.h
+++ b/chrome/browser/ui/autofill/autofill_popup_controller_impl.h
@@ -52,9 +52,9 @@ class AutofillPopupControllerImpl : public AutofillPopupController {
       base::i18n::TextDirection text_direction);
 
   // Shows the popup, or updates the existing popup with the given values.
-  void Show(const std::vector<string16>& names,
-            const std::vector<string16>& subtexts,
-            const std::vector<string16>& icons,
+  void Show(const std::vector<base::string16>& names,
+            const std::vector<base::string16>& subtexts,
+            const std::vector<base::string16>& icons,
             const std::vector<int>& identifiers);
 
   // Updates the data list values currently shown with the popup.
@@ -93,7 +93,8 @@ class AutofillPopupControllerImpl : public AutofillPopupController {
   virtual void SelectionCleared() OVERRIDE;
   virtual bool ShouldRepostEvent(const ui::MouseEvent& event) OVERRIDE;
   virtual void AcceptSuggestion(size_t index) OVERRIDE;
-  virtual int GetIconResourceID(const string16& resource_name) const OVERRIDE;
+  virtual int GetIconResourceID(
+      const base::string16& resource_name) const OVERRIDE;
   virtual bool CanDelete(size_t index) const OVERRIDE;
   virtual bool IsWarning(size_t index) const OVERRIDE;
   virtual gfx::Rect GetRowBounds(size_t index) OVERRIDE;
@@ -103,9 +104,9 @@ class AutofillPopupControllerImpl : public AutofillPopupController {
   virtual const gfx::RectF& element_bounds() const OVERRIDE;
   virtual bool IsRTL() const OVERRIDE;
 
-  virtual const std::vector<string16>& names() const OVERRIDE;
-  virtual const std::vector<string16>& subtexts() const OVERRIDE;
-  virtual const std::vector<string16>& icons() const OVERRIDE;
+  virtual const std::vector<base::string16>& names() const OVERRIDE;
+  virtual const std::vector<base::string16>& subtexts() const OVERRIDE;
+  virtual const std::vector<base::string16>& icons() const OVERRIDE;
   virtual const std::vector<int>& identifiers() const OVERRIDE;
 #if !defined(OS_ANDROID)
   virtual const gfx::Font& GetNameFontForRow(size_t index) const OVERRIDE;
@@ -143,9 +144,9 @@ class AutofillPopupControllerImpl : public AutofillPopupController {
 
   // Set the Autofill entry values. Exposed to allow tests to set these values
   // without showing the popup.
-  void SetValues(const std::vector<string16>& names,
-                 const std::vector<string16>& subtexts,
-                 const std::vector<string16>& icons,
+  void SetValues(const std::vector<base::string16>& names,
+                 const std::vector<base::string16>& subtexts,
+                 const std::vector<base::string16>& icons,
                  const std::vector<int>& identifier);
 
   AutofillPopupView* view() { return view_; }
@@ -225,14 +226,14 @@ class AutofillPopupControllerImpl : public AutofillPopupController {
   content::RenderViewHost* registered_key_press_event_callback_with_;
 
   // The current Autofill query values.
-  std::vector<string16> names_;
-  std::vector<string16> subtexts_;
-  std::vector<string16> icons_;
+  std::vector<base::string16> names_;
+  std::vector<base::string16> subtexts_;
+  std::vector<base::string16> icons_;
   std::vector<int> identifiers_;
 
   // Since names_ can be elided to ensure that it fits on the screen, we need to
   // keep an unelided copy of the names to be able to pass to the delegate.
-  std::vector<string16> full_names_;
+  std::vector<base::string16> full_names_;
 
 #if !defined(OS_ANDROID)
   // The fonts for the popup text.
diff --git a/chrome/browser/ui/autofill/autofill_popup_controller_unittest.cc b/chrome/browser/ui/autofill/autofill_popup_controller_unittest.cc
index f0e1df0..7979885 100644
--- a/chrome/browser/ui/autofill/autofill_popup_controller_unittest.cc
+++ b/chrome/browser/ui/autofill/autofill_popup_controller_unittest.cc
@@ -41,8 +41,8 @@ class MockAutofillExternalDelegate : public AutofillExternalDelegate {
   virtual ~MockAutofillExternalDelegate() {}
 
   virtual void DidSelectSuggestion(int identifier) OVERRIDE {}
-  virtual void RemoveSuggestion(const string16& value, int identifier) OVERRIDE
-      {}
+  virtual void RemoveSuggestion(const base::string16& value,
+                                int identifier) OVERRIDE {}
   virtual void ClearPreviewedForm() OVERRIDE {}
   base::WeakPtr<AutofillExternalDelegate> GetWeakPtr() {
     return AutofillExternalDelegate::GetWeakPtr();
@@ -185,7 +185,7 @@ TEST_F(AutofillPopupControllerUnitTest, SetBounds) {
 
 TEST_F(AutofillPopupControllerUnitTest, ChangeSelectedLine) {
   // Set up the popup.
-  std::vector<string16> names(2, string16());
+  std::vector<base::string16> names(2, base::string16());
   std::vector<int> autofill_ids(2, 0);
   autofill_popup_controller_->Show(names, names, names, autofill_ids);
 
@@ -208,7 +208,7 @@ TEST_F(AutofillPopupControllerUnitTest, ChangeSelectedLine) {
 
 TEST_F(AutofillPopupControllerUnitTest, RedrawSelectedLine) {
   // Set up the popup.
-  std::vector<string16> names(2, string16());
+  std::vector<base::string16> names(2, base::string16());
   std::vector<int> autofill_ids(2, 0);
   autofill_popup_controller_->Show(names, names, names, autofill_ids);
 
@@ -230,7 +230,7 @@ TEST_F(AutofillPopupControllerUnitTest, RedrawSelectedLine) {
 
 TEST_F(AutofillPopupControllerUnitTest, RemoveLine) {
   // Set up the popup.
-  std::vector<string16> names(3, string16());
+  std::vector<base::string16> names(3, base::string16());
   std::vector<int> autofill_ids;
   autofill_ids.push_back(1);
   autofill_ids.push_back(1);
@@ -266,7 +266,7 @@ TEST_F(AutofillPopupControllerUnitTest, RemoveLine) {
 
 TEST_F(AutofillPopupControllerUnitTest, RemoveOnlyLine) {
   // Set up the popup.
-  std::vector<string16> names(1, string16());
+  std::vector<base::string16> names(1, base::string16());
   std::vector<int> autofill_ids;
   autofill_ids.push_back(1);
   autofill_popup_controller_->Show(names, names, names, autofill_ids);
@@ -286,7 +286,7 @@ TEST_F(AutofillPopupControllerUnitTest, RemoveOnlyLine) {
 
 TEST_F(AutofillPopupControllerUnitTest, SkipSeparator) {
   // Set up the popup.
-  std::vector<string16> names(3, string16());
+  std::vector<base::string16> names(3, base::string16());
   std::vector<int> autofill_ids;
   autofill_ids.push_back(1);
   autofill_ids.push_back(WebAutofillClient::MenuItemIDSeparator);
@@ -305,9 +305,9 @@ TEST_F(AutofillPopupControllerUnitTest, SkipSeparator) {
 }
 
 TEST_F(AutofillPopupControllerUnitTest, RowWidthWithoutText) {
-  std::vector<string16> names(4);
-  std::vector<string16> subtexts(4);
-  std::vector<string16> icons(4);
+  std::vector<base::string16> names(4);
+  std::vector<base::string16> subtexts(4);
+  std::vector<base::string16> icons(4);
   std::vector<int> ids(4);
 
   // Set up some visible display so the text values are kept.
@@ -341,7 +341,7 @@ TEST_F(AutofillPopupControllerUnitTest, RowWidthWithoutText) {
 }
 
 TEST_F(AutofillPopupControllerUnitTest, UpdateDataListValues) {
-  std::vector<string16> items;
+  std::vector<base::string16> items;
   items.push_back(string16());
   std::vector<int> ids;
   ids.push_back(1);
@@ -352,7 +352,7 @@ TEST_F(AutofillPopupControllerUnitTest, UpdateDataListValues) {
   EXPECT_EQ(ids, autofill_popup_controller_->identifiers());
 
   // Add one data list entry.
-  std::vector<string16> data_list_values;
+  std::vector<base::string16> data_list_values;
   data_list_values.push_back(ASCIIToUTF16("data list value 1"));
 
   autofill_popup_controller_->UpdateDataListValues(data_list_values,
@@ -360,7 +360,7 @@ TEST_F(AutofillPopupControllerUnitTest, UpdateDataListValues) {
 
   // Update the expected values.
   items.insert(items.begin(), data_list_values[0]);
-  items.insert(items.begin() + 1, string16());
+  items.insert(items.begin() + 1, base::string16());
   ids.insert(ids.begin(), WebAutofillClient::MenuItemIDDataListEntry);
   ids.insert(ids.begin() + 1, WebAutofillClient::MenuItemIDSeparator);
 
@@ -397,7 +397,7 @@ TEST_F(AutofillPopupControllerUnitTest, UpdateDataListValues) {
 
 TEST_F(AutofillPopupControllerUnitTest, PopupsWithOnlyDataLists) {
   // Create the popup with a single datalist element.
-  std::vector<string16> items;
+  std::vector<base::string16> items;
   items.push_back(string16());
   std::vector<int> ids;
   ids.push_back(WebAutofillClient::MenuItemIDDataListEntry);
@@ -408,7 +408,7 @@ TEST_F(AutofillPopupControllerUnitTest, PopupsWithOnlyDataLists) {
   EXPECT_EQ(ids, autofill_popup_controller_->identifiers());
 
   // Replace the datalist element with a new one.
-  std::vector<string16> data_list_values;
+  std::vector<base::string16> data_list_values;
   data_list_values.push_back(ASCIIToUTF16("data list value 1"));
 
   autofill_popup_controller_->UpdateDataListValues(data_list_values,
@@ -478,7 +478,7 @@ TEST_F(AutofillPopupControllerUnitTest, GetOrCreate) {
 }
 
 TEST_F(AutofillPopupControllerUnitTest, ProperlyResetController) {
-  std::vector<string16> names(2);
+  std::vector<base::string16> names(2);
   std::vector<int> ids(2);
   popup_controller()->SetValues(names, names, names, ids);
   popup_controller()->SetSelectedLine(0);
@@ -498,15 +498,15 @@ TEST_F(AutofillPopupControllerUnitTest, ProperlyResetController) {
 
 #if !defined(OS_ANDROID)
 TEST_F(AutofillPopupControllerUnitTest, ElideText) {
-  std::vector<string16> names;
+  std::vector<base::string16> names;
   names.push_back(ASCIIToUTF16("Text that will need to be trimmed"));
   names.push_back(ASCIIToUTF16("Untrimmed"));
 
-  std::vector<string16> subtexts;
+  std::vector<base::string16> subtexts;
   subtexts.push_back(ASCIIToUTF16("Label that will be trimmed"));
   subtexts.push_back(ASCIIToUTF16("Untrimmed"));
 
-  std::vector<string16> icons(2, ASCIIToUTF16("genericCC"));
+  std::vector<base::string16> icons(2, ASCIIToUTF16("genericCC"));
   std::vector<int> autofill_ids(2, 0);
 
   // Show the popup once so we can easily generate the size it needs.
@@ -534,7 +534,7 @@ TEST_F(AutofillPopupControllerUnitTest, ElideText) {
 #endif
 
 TEST_F(AutofillPopupControllerUnitTest, GrowPopupInSpace) {
-  std::vector<string16> names(1);
+  std::vector<base::string16> names(1);
   std::vector<int> autofill_ids(1, 1);
 
   // Call Show so that GetDesired...() will be able to provide valid values.
diff --git a/chrome/browser/ui/autofill/country_combobox_model.h b/chrome/browser/ui/autofill/country_combobox_model.h
index 40c4202..74afeae 100644
--- a/chrome/browser/ui/autofill/country_combobox_model.h
+++ b/chrome/browser/ui/autofill/country_combobox_model.h
@@ -25,7 +25,7 @@ class CountryComboboxModel : public ui::ComboboxModel {
 
   // ui::Combobox implementation:
   virtual int GetItemCount() const OVERRIDE;
-  virtual string16 GetItemAt(int index) OVERRIDE;
+  virtual base::string16 GetItemAt(int index) OVERRIDE;
   virtual bool IsItemSeparatorAt(int index) OVERRIDE;
 
   const std::vector<AutofillCountry*>& countries() const {
diff --git a/chrome/browser/ui/autofill/data_model_wrapper_unittest.cc b/chrome/browser/ui/autofill/data_model_wrapper_unittest.cc
index e5a8490..5dc0d24 100644
--- a/chrome/browser/ui/autofill/data_model_wrapper_unittest.cc
+++ b/chrome/browser/ui/autofill/data_model_wrapper_unittest.cc
@@ -91,7 +91,7 @@ TEST(DataModelWrapperTest, GetDisplayTextEmptyWithoutPhone) {
   EXPECT_TRUE(address_wrapper.GetDisplayText(&unused, &unused2));
 
   const_cast<wallet::Address*>(&instrument->address())->SetPhoneNumber(
-      string16());
+      base::string16());
 
   EXPECT_EQ(base::string16(),
             instrument_wrapper.GetInfo(AutofillType(PHONE_HOME_WHOLE_NUMBER)));
diff --git a/chrome/browser/ui/autofill/mock_autofill_dialog_view_delegate.cc b/chrome/browser/ui/autofill/mock_autofill_dialog_view_delegate.cc
index 1aaef16..65ea225 100644
--- a/chrome/browser/ui/autofill/mock_autofill_dialog_view_delegate.cc
+++ b/chrome/browser/ui/autofill/mock_autofill_dialog_view_delegate.cc
@@ -26,10 +26,10 @@ MockAutofillDialogViewDelegate::MockAutofillDialogViewDelegate() {
   DefaultValue<ValidityMessages>::Set(ValidityMessages());
   DefaultValue<gfx::Image>::Set(gfx::Image());
   DefaultValue<SuggestionState>::Set(SuggestionState(false,
-                                                     string16(),
-                                                     string16(),
+                                                     base::string16(),
+                                                     base::string16(),
                                                      gfx::Image(),
-                                                     string16(),
+                                                     base::string16(),
                                                      gfx::Image()));
   DefaultValue<FieldIconMap>::Set(FieldIconMap());
   DefaultValue<std::vector<DialogNotification> >::Set(
diff --git a/chrome/browser/ui/autofill/mock_autofill_dialog_view_delegate.h b/chrome/browser/ui/autofill/mock_autofill_dialog_view_delegate.h
index 1de57cd..34947f5 100644
--- a/chrome/browser/ui/autofill/mock_autofill_dialog_view_delegate.h
+++ b/chrome/browser/ui/autofill/mock_autofill_dialog_view_delegate.h
@@ -17,16 +17,16 @@ class MockAutofillDialogViewDelegate : public AutofillDialogViewDelegate {
   MockAutofillDialogViewDelegate();
   virtual ~MockAutofillDialogViewDelegate();
 
-  MOCK_CONST_METHOD0(DialogTitle, string16());
-  MOCK_CONST_METHOD0(AccountChooserText, string16());
-  MOCK_CONST_METHOD0(SignInLinkText, string16());
-  MOCK_CONST_METHOD0(SpinnerText, string16());
-  MOCK_CONST_METHOD0(EditSuggestionText, string16());
-  MOCK_CONST_METHOD0(CancelButtonText, string16());
-  MOCK_CONST_METHOD0(ConfirmButtonText, string16());
-  MOCK_CONST_METHOD0(SaveLocallyText, string16());
-  MOCK_CONST_METHOD0(SaveLocallyTooltip, string16());
-  MOCK_METHOD0(LegalDocumentsText, string16());
+  MOCK_CONST_METHOD0(DialogTitle, base::string16());
+  MOCK_CONST_METHOD0(AccountChooserText, base::string16());
+  MOCK_CONST_METHOD0(SignInLinkText, base::string16());
+  MOCK_CONST_METHOD0(SpinnerText, base::string16());
+  MOCK_CONST_METHOD0(EditSuggestionText, base::string16());
+  MOCK_CONST_METHOD0(CancelButtonText, base::string16());
+  MOCK_CONST_METHOD0(ConfirmButtonText, base::string16());
+  MOCK_CONST_METHOD0(SaveLocallyText, base::string16());
+  MOCK_CONST_METHOD0(SaveLocallyTooltip, base::string16());
+  MOCK_METHOD0(LegalDocumentsText, base::string16());
   MOCK_CONST_METHOD0(ShouldShowSpinner, bool());
   MOCK_CONST_METHOD0(ShouldShowSignInWebView, bool());
   MOCK_CONST_METHOD0(SignInUrl, GURL());
@@ -46,7 +46,7 @@ class MockAutofillDialogViewDelegate : public AutofillDialogViewDelegate {
   MOCK_METHOD1(ComboboxModelForAutofillType,
                ui::ComboboxModel*(ServerFieldType));
   MOCK_METHOD1(MenuModelForSection, ui::MenuModel*(DialogSection));
-  MOCK_CONST_METHOD1(LabelForSection, string16(DialogSection section));
+  MOCK_CONST_METHOD1(LabelForSection, base::string16(DialogSection section));
   MOCK_METHOD1(SuggestionStateForSection, SuggestionState(DialogSection));
   MOCK_METHOD1(EditClickedForSection, void(DialogSection section));
   MOCK_METHOD1(EditCancelledForSection, void(DialogSection section));
@@ -56,14 +56,14 @@ class MockAutofillDialogViewDelegate : public AutofillDialogViewDelegate {
   MOCK_METHOD2(InputIsEditable, bool(const DetailInput& input,
                                      DialogSection section));
   MOCK_METHOD3(InputValidityMessage,
-      string16(DialogSection, ServerFieldType, const string16&));
+      base::string16(DialogSection, ServerFieldType, const base::string16&));
   MOCK_METHOD2(InputsAreValid, ValidityMessages(DialogSection,
                                                 const FieldValueMap&));
   MOCK_METHOD6(UserEditedOrActivatedInput, void(DialogSection,
                                                 ServerFieldType,
                                                 gfx::NativeView,
                                                 const gfx::Rect&,
-                                                const string16&,
+                                                const base::string16&,
                                                 bool was_edit));
   MOCK_METHOD1(HandleKeyPressEventInInput,
                bool(const content::NativeWebKeyboardEvent& event));
diff --git a/chrome/browser/ui/autofill/testable_autofill_dialog_view.h b/chrome/browser/ui/autofill/testable_autofill_dialog_view.h
index 632e7e9..5ae09b8 100644
--- a/chrome/browser/ui/autofill/testable_autofill_dialog_view.h
+++ b/chrome/browser/ui/autofill/testable_autofill_dialog_view.h
@@ -20,11 +20,11 @@ class TestableAutofillDialogView {
   virtual void CancelForTesting() = 0;
 
   // Returns the actual contents of the input which is modelled by |input|.
-  virtual string16 GetTextContentsOfInput(const DetailInput& input) = 0;
+  virtual base::string16 GetTextContentsOfInput(const DetailInput& input) = 0;
 
   // Sets the actual contents of the input which is modelled by |input|.
   virtual void SetTextContentsOfInput(const DetailInput& input,
-                                      const string16& contents) = 0;
+                                      const base::string16& contents) = 0;
 
   // Sets the content of the extra field for a section.
   virtual void SetTextContentsOfSuggestionInput(DialogSection section,
diff --git a/chrome/browser/ui/browser.cc b/chrome/browser/ui/browser.cc
index 9a52aa8..e56a0b6 100644
--- a/chrome/browser/ui/browser.cc
+++ b/chrome/browser/ui/browser.cc
@@ -546,9 +546,9 @@ gfx::Image Browser::GetCurrentPageIcon() const {
   return favicon_tab_helper ? favicon_tab_helper->GetFavicon() : gfx::Image();
 }
 
-string16 Browser::GetWindowTitleForCurrentTab() const {
+base::string16 Browser::GetWindowTitleForCurrentTab() const {
   WebContents* contents = tab_strip_model_->GetActiveWebContents();
-  string16 title;
+  base::string16 title;
 
   // |contents| can be NULL because GetWindowTitleForCurrentTab is called by the
   // window during the window's creation (before tabs have been added).
@@ -577,11 +577,12 @@ string16 Browser::GetWindowTitleForCurrentTab() const {
 }
 
 // static
-void Browser::FormatTitleForDisplay(string16* title) {
+void Browser::FormatTitleForDisplay(base::string16* title) {
   size_t current_index = 0;
   size_t match_index;
-  while ((match_index = title->find(L'\n', current_index)) != string16::npos) {
-    title->replace(match_index, 1, string16());
+  while ((match_index = title->find(L'\n', current_index)) !=
+         base::string16::npos) {
+    title->replace(match_index, 1, base::string16());
     current_index = match_index;
   }
 }
@@ -829,7 +830,7 @@ void Browser::OpenFile() {
   ui::SelectFileDialog::FileTypeInfo file_types;
   file_types.support_drive = true;
   select_file_dialog_->SelectFile(ui::SelectFileDialog::SELECT_OPEN_FILE,
-                                  string16(),
+                                  base::string16(),
                                   directory,
                                   &file_types,
                                   0,
@@ -874,7 +875,7 @@ void Browser::JSOutOfMemoryHelper(WebContents* web_contents) {
 void Browser::RegisterProtocolHandlerHelper(WebContents* web_contents,
                                             const std::string& protocol,
                                             const GURL& url,
-                                            const string16& title,
+                                            const base::string16& title,
                                             bool user_gesture,
                                             BrowserWindow* window) {
   Profile* profile =
@@ -1521,7 +1522,7 @@ bool Browser::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,
     content::SessionStorageNamespace* session_storage_namespace) {
@@ -1540,7 +1541,7 @@ bool Browser::ShouldCreateWebContents(
 
 void Browser::WebContentsCreated(WebContents* source_contents,
                                  int64 source_frame_id,
-                                 const string16& frame_name,
+                                 const base::string16& frame_name,
                                  const GURL& target_url,
                                  WebContents* new_contents) {
   // Adopt the WebContents now, so all observers are in place, as the network
@@ -1638,7 +1639,7 @@ void Browser::JSOutOfMemory(WebContents* web_contents) {
 void Browser::RegisterProtocolHandler(WebContents* web_contents,
                                       const std::string& protocol,
                                       const GURL& url,
-                                      const string16& title,
+                                      const base::string16& title,
                                       bool user_gesture) {
   RegisterProtocolHandlerHelper(
       web_contents, protocol, url, title, user_gesture, window());
@@ -2223,7 +2224,7 @@ bool Browser::ShouldHideUIForFullscreen() const {
 bool Browser::MaybeCreateBackgroundContents(
     int route_id,
     WebContents* opener_web_contents,
-    const string16& frame_name,
+    const base::string16& frame_name,
     const GURL& target_url,
     const std::string& partition_id,
     content::SessionStorageNamespace* session_storage_namespace) {
diff --git a/chrome/browser/ui/browser.h b/chrome/browser/ui/browser.h
index b53ee9e..f5e25ea 100644
--- a/chrome/browser/ui/browser.h
+++ b/chrome/browser/ui/browser.h
@@ -285,7 +285,7 @@ class Browser : public TabStripModelObserver,
   gfx::Image GetCurrentPageIcon() const;
 
   // Gets the title of the window based on the selected tab's title.
-  string16 GetWindowTitleForCurrentTab() const;
+  base::string16 GetWindowTitleForCurrentTab() const;
 
   // Prepares a title string for display (removes embedded newlines, etc).
   static void FormatTitleForDisplay(string16* title);
@@ -407,7 +407,7 @@ class Browser : public TabStripModelObserver,
   static void RegisterProtocolHandlerHelper(content::WebContents* web_contents,
                                             const std::string& protocol,
                                             const GURL& url,
-                                            const string16& title,
+                                            const base::string16& title,
                                             bool user_gesture,
                                             BrowserWindow* window);
 
@@ -596,13 +596,13 @@ class Browser : public TabStripModelObserver,
       content::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,
       content::SessionStorageNamespace* session_storage_namespace) OVERRIDE;
   virtual void WebContentsCreated(content::WebContents* source_contents,
                                   int64 source_frame_id,
-                                  const string16& frame_name,
+                                  const base::string16& frame_name,
                                   const GURL& target_url,
                                   content::WebContents* new_contents) OVERRIDE;
   virtual void RendererUnresponsive(content::WebContents* source) OVERRIDE;
@@ -633,7 +633,7 @@ class Browser : public TabStripModelObserver,
   virtual void RegisterProtocolHandler(content::WebContents* web_contents,
                                        const std::string& protocol,
                                        const GURL& url,
-                                       const string16& title,
+                                       const base::string16& title,
                                        bool user_gesture) OVERRIDE;
   virtual void UpdatePreferredSize(content::WebContents* source,
                                    const gfx::Size& pref_size) OVERRIDE;
@@ -804,7 +804,7 @@ class Browser : public TabStripModelObserver,
   bool MaybeCreateBackgroundContents(
       int route_id,
       content::WebContents* opener_web_contents,
-      const string16& frame_name,
+      const base::string16& frame_name,
       const GURL& target_url,
       const std::string& partition_id,
       content::SessionStorageNamespace* session_storage_namespace);
diff --git a/chrome/browser/ui/browser_command_controller.cc b/chrome/browser/ui/browser_command_controller.cc
index dd30b83..6fdff5f 100644
--- a/chrome/browser/ui/browser_command_controller.cc
+++ b/chrome/browser/ui/browser_command_controller.cc
@@ -773,7 +773,7 @@ void BrowserCommandController::OnProfileAdded(
 
 void BrowserCommandController::OnProfileWasRemoved(
     const base::FilePath& profile_path,
-    const string16& profile_name) {
+    const base::string16& profile_name) {
   UpdateCommandsForMultipleProfiles();
 }
 
diff --git a/chrome/browser/ui/browser_command_controller.h b/chrome/browser/ui/browser_command_controller.h
index f46751c..da9e995 100644
--- a/chrome/browser/ui/browser_command_controller.h
+++ b/chrome/browser/ui/browser_command_controller.h
@@ -87,7 +87,7 @@ class BrowserCommandController : public CommandUpdaterDelegate,
   // Overridden from ProfileInfoCacheObserver:
   virtual void OnProfileAdded(const base::FilePath& profile_path) OVERRIDE;
   virtual void OnProfileWasRemoved(const base::FilePath& profile_path,
-                                   const string16& profile_name) OVERRIDE;
+                                   const base::string16& profile_name) OVERRIDE;
 
   // Overridden from TabStripModelObserver:
   virtual void TabInsertedAt(content::WebContents* contents,
diff --git a/chrome/browser/ui/browser_commands.cc b/chrome/browser/ui/browser_commands.cc
index c36442b..4c86d3e 100644
--- a/chrome/browser/ui/browser_commands.cc
+++ b/chrome/browser/ui/browser_commands.cc
@@ -115,7 +115,7 @@ void BookmarkCurrentPageInternal(Browser* browser, bool from_star) {
     return;  // Ignore requests until bookmarks are loaded.
 
   GURL url;
-  string16 title;
+  base::string16 title;
   WebContents* web_contents =
       browser->tab_strip_model()->GetActiveWebContents();
   GetURLAndTitleToBookmark(web_contents, &url, &title);
@@ -855,7 +855,7 @@ void FindPrevious(Browser* browser) {
 void FindInPage(Browser* browser, bool find_next, bool forward_direction) {
   ShowFindBar(browser);
   if (find_next) {
-    string16 find_text;
+    base::string16 find_text;
     FindTabHelper* find_helper = FindTabHelper::FromWebContents(
         browser->tab_strip_model()->GetActiveWebContents());
 #if defined(OS_MACOSX)
diff --git a/chrome/browser/ui/browser_instant_controller.cc b/chrome/browser/ui/browser_instant_controller.cc
index e73c625..b30da97 100644
--- a/chrome/browser/ui/browser_instant_controller.cc
+++ b/chrome/browser/ui/browser_instant_controller.cc
@@ -122,7 +122,7 @@ bool BrowserInstantController::OpenInstant(WindowOpenDisposition disposition,
 
   // If we will not be replacing search terms from this URL, don't send to
   // InstantController.
-  const string16& search_terms =
+  const base::string16& search_terms =
       chrome::GetSearchTermsFromURL(browser_->profile(), url);
   if (search_terms.empty())
     return false;
diff --git a/chrome/browser/ui/browser_window.h b/chrome/browser/ui/browser_window.h
index a9c19e0..951c6ba 100644
--- a/chrome/browser/ui/browser_window.h
+++ b/chrome/browser/ui/browser_window.h
@@ -247,8 +247,8 @@ class BrowserWindow : public ui::BaseWindow {
   // of the account that has signed in.
   virtual void ShowOneClickSigninBubble(
       OneClickSigninBubbleType type,
-      const string16& email,
-      const string16& error_message,
+      const base::string16& email,
+      const base::string16& error_message,
       const StartSyncCallback& start_sync_callback) = 0;
 #endif
 
diff --git a/chrome/browser/ui/certificate_dialogs.cc b/chrome/browser/ui/certificate_dialogs.cc
index fbc0825..d200036 100644
--- a/chrome/browser/ui/certificate_dialogs.cc
+++ b/chrome/browser/ui/certificate_dialogs.cc
@@ -171,7 +171,7 @@ void ShowCertSelectFileDialog(ui::SelectFileDialog* select_file_dialog,
       l10n_util::GetStringUTF16(IDS_CERT_EXPORT_TYPE_PKCS7_CHAIN));
   file_type_info.include_all_files = true;
   select_file_dialog->SelectFile(
-      type, string16(),
+      type, base::string16(),
       suggested_path, &file_type_info,
       1,  // 1-based index for |file_type_info.extensions| to specify default.
       FILE_PATH_LITERAL("crt"),
diff --git a/chrome/browser/ui/cocoa/applescript/bookmark_folder_applescript.mm b/chrome/browser/ui/cocoa/applescript/bookmark_folder_applescript.mm
index cc9ff82..e7008b7 100644
--- a/chrome/browser/ui/cocoa/applescript/bookmark_folder_applescript.mm
+++ b/chrome/browser/ui/cocoa/applescript/bookmark_folder_applescript.mm
@@ -45,7 +45,7 @@
 
   const BookmarkNode* node = model->AddFolder(bookmarkNode_,
                                               bookmarkNode_->child_count(),
-                                              string16());
+                                              base::string16());
   if (!node) {
     AppleScript::SetError(AppleScript::errCreateBookmarkFolder);
     return;
@@ -67,7 +67,7 @@
 
   const BookmarkNode* node = model->AddFolder(bookmarkNode_,
                                               position,
-                                              string16());
+                                              base::string16());
   if (!node) {
     AppleScript::SetError(AppleScript::errCreateBookmarkFolder);
     return;
@@ -123,7 +123,7 @@
 
   const BookmarkNode* node = model->AddURL(bookmarkNode_,
                                            bookmarkNode_->child_count(),
-                                           string16(),
+                                           base::string16(),
                                            url);
   if (!node) {
     AppleScript::SetError(AppleScript::errCreateBookmarkItem);
@@ -153,7 +153,7 @@
 
   const BookmarkNode* node = model->AddURL(bookmarkNode_,
                                            position,
-                                           string16(),
+                                           base::string16(),
                                            url);
   if (!node) {
     AppleScript::SetError(AppleScript::errCreateBookmarkItem);
diff --git a/chrome/browser/ui/cocoa/applescript/tab_applescript.mm b/chrome/browser/ui/cocoa/applescript/tab_applescript.mm
index a8afbb8..be4e1ffa 100644
--- a/chrome/browser/ui/cocoa/applescript/tab_applescript.mm
+++ b/chrome/browser/ui/cocoa/applescript/tab_applescript.mm
@@ -154,7 +154,7 @@ void ResumeAppleEventAndSendReply(NSAppleEventManagerSuspensionID suspension_id,
   if (!entry)
     return nil;
 
-  string16 title = entry ? entry->GetTitle() : string16();
+  base::string16 title = entry ? entry->GetTitle() : base::string16();
   return base::SysUTF16ToNSString(title);
 }
 
@@ -327,7 +327,7 @@ void ResumeAppleEventAndSendReply(NSAppleEventManagerSuspensionID suspension_id,
   content::RenderViewHost::JavascriptResultCallback callback =
       base::Bind(&ResumeAppleEventAndSendReply, suspensionID);
 
-  string16 script = base::SysNSStringToUTF16(
+  base::string16 script = base::SysNSStringToUTF16(
       [[command evaluatedArguments] objectForKey:@"javascript"]);
   view->ExecuteJavascriptInWebFrameCallbackResult(string16(),  // frame_xpath
                                                   script,
diff --git a/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.h b/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.h
index 87374bf..6f1442e 100644
--- a/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.h
+++ b/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.h
@@ -50,7 +50,7 @@ class AutofillDialogCocoa : public AutofillDialogView,
                            const DetailInput& originating_input) OVERRIDE;
   virtual void GetUserInput(DialogSection section,
                             FieldValueMap* output) OVERRIDE;
-  virtual string16 GetCvc() OVERRIDE;
+  virtual base::string16 GetCvc() OVERRIDE;
   virtual bool HitTestInput(const DetailInput& input,
                             const gfx::Point& screen_point) OVERRIDE;
   virtual bool SaveDetailsLocally() OVERRIDE;
@@ -65,9 +65,10 @@ class AutofillDialogCocoa : public AutofillDialogView,
   // http://crbug.com/256864
   virtual void SubmitForTesting() OVERRIDE;
   virtual void CancelForTesting() OVERRIDE;
-  virtual string16 GetTextContentsOfInput(const DetailInput& input) OVERRIDE;
+  virtual base::string16 GetTextContentsOfInput(
+      const DetailInput& input) OVERRIDE;
   virtual void SetTextContentsOfInput(const DetailInput& input,
-                                      const string16& contents) OVERRIDE;
+                                      const base::string16& contents) OVERRIDE;
   virtual void SetTextContentsOfSuggestionInput(
       DialogSection section,
       const base::string16& text) OVERRIDE;
diff --git a/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.mm b/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.mm
index 571c4ca..582c031 100644
--- a/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.mm
+++ b/chrome/browser/ui/cocoa/autofill/autofill_dialog_cocoa.mm
@@ -104,7 +104,7 @@ void AutofillDialogCocoa::GetUserInput(DialogSection section,
   [sheet_delegate_ getInputs:output forSection:section];
 }
 
-string16 AutofillDialogCocoa::GetCvc() {
+base::string16 AutofillDialogCocoa::GetCvc() {
   return base::SysNSStringToUTF16([sheet_delegate_ getCvc]);
 }
 
@@ -151,7 +151,8 @@ void AutofillDialogCocoa::CancelForTesting() {
   [sheet_delegate_ cancel:nil];
 }
 
-string16 AutofillDialogCocoa::GetTextContentsOfInput(const DetailInput& input) {
+base::string16 AutofillDialogCocoa::GetTextContentsOfInput(
+    const DetailInput& input) {
   for (size_t i = SECTION_MIN; i <= SECTION_MAX; ++i) {
     DialogSection section = static_cast<DialogSection>(i);
     FieldValueMap contents;
@@ -162,11 +163,12 @@ string16 AutofillDialogCocoa::GetTextContentsOfInput(const DetailInput& input) {
   }
 
   NOTREACHED();
-  return string16();
+  return base::string16();
 }
 
-void AutofillDialogCocoa::SetTextContentsOfInput(const DetailInput& input,
-                                                 const string16& contents) {
+void AutofillDialogCocoa::SetTextContentsOfInput(
+    const DetailInput& input,
+    const base::string16& contents) {
   [sheet_delegate_ setTextContents:base::SysUTF16ToNSString(contents)
                           forInput:input];
 }
diff --git a/chrome/browser/ui/cocoa/autofill/autofill_section_container.mm b/chrome/browser/ui/cocoa/autofill/autofill_section_container.mm
index fd38bd5..d61330f 100644
--- a/chrome/browser/ui/cocoa/autofill/autofill_section_container.mm
+++ b/chrome/browser/ui/cocoa/autofill/autofill_section_container.mm
@@ -179,7 +179,7 @@ bool ShouldOverwriteComboboxes(autofill::DialogSection section,
   }
 
   inputs_.reset([[self makeInputControls] retain]);
-  string16 labelText = delegate_->LabelForSection(section_);
+  base::string16 labelText = delegate_->LabelForSection(section_);
   label_.reset(
       [[self makeDetailSectionLabel:base::SysUTF16ToNSString(labelText)]
           retain]);
@@ -405,7 +405,7 @@ bool ShouldOverwriteComboboxes(autofill::DialogSection section,
     return;
 
   autofill::ServerFieldType type = [self fieldTypeForControl:field];
-  string16 fieldValue = base::SysNSStringToUTF16([textfield fieldValue]);
+  base::string16 fieldValue = base::SysNSStringToUTF16([textfield fieldValue]);
 
   // Get the frame rectangle for the designated field, in screen coordinates.
   NSRect textFrameInScreen = [field convertRect:[field bounds] toView:nil];
@@ -431,7 +431,7 @@ bool ShouldOverwriteComboboxes(autofill::DialogSection section,
   // correcting a minor mistake (i.e. a wrong CC digit) should immediately
   // result in validation - positive user feedback.
   if ([textfield invalid] && edited) {
-    string16 message = delegate_->InputValidityMessage(section_,
+    base::string16 message = delegate_->InputValidityMessage(section_,
                                                        type,
                                                        fieldValue);
     [textfield setValidityMessage:base::SysUTF16ToNSString(message)];
diff --git a/chrome/browser/ui/cocoa/browser/avatar_button_controller.mm b/chrome/browser/ui/cocoa/browser/avatar_button_controller.mm
index cfff00c..7fba944 100644
--- a/chrome/browser/ui/cocoa/browser/avatar_button_controller.mm
+++ b/chrome/browser/ui/cocoa/browser/avatar_button_controller.mm
@@ -311,7 +311,7 @@ class Observer : public content::NotificationObserver {
       profiles::kAvatarIconWidth, profiles::kAvatarIconHeight);
   [self setImage:icon.ToNSImage()];
 
-  const string16& name = cache.GetNameOfProfileAtIndex(index);
+  const base::string16& name = cache.GetNameOfProfileAtIndex(index);
   NSString* nsName = base::SysUTF16ToNSString(name);
   [button_ setToolTip:nsName];
   [[button_ cell]
diff --git a/chrome/browser/ui/cocoa/browser/edit_search_engine_cocoa_controller.mm b/chrome/browser/ui/cocoa/browser/edit_search_engine_cocoa_controller.mm
index 6e1d05c..ae36e5c 100644
--- a/chrome/browser/ui/cocoa/browser/edit_search_engine_cocoa_controller.mm
+++ b/chrome/browser/ui/cocoa/browser/edit_search_engine_cocoa_controller.mm
@@ -120,8 +120,9 @@ void ShiftOriginY(NSView* view, CGFloat amount) {
 
 - (IBAction)save:(id)sender {
   DCHECK([self validateFields]);
-  string16 title = base::SysNSStringToUTF16([nameField_ stringValue]);
-  string16 keyword = base::SysNSStringToUTF16([keywordField_ stringValue]);
+  base::string16 title = base::SysNSStringToUTF16([nameField_ stringValue]);
+  base::string16 keyword =
+      base::SysNSStringToUTF16([keywordField_ stringValue]);
   std::string url = base::SysNSStringToUTF8([urlField_ stringValue]);
   controller_->AcceptAddOrEdit(title, keyword, url);
   [self doClose];
@@ -159,14 +160,15 @@ void ShiftOriginY(NSView* view, CGFloat amount) {
 // This sets the image state for all the controls and enables or disables the
 // done button. Returns YES if all the fields are valid.
 - (BOOL)validateFields {
-  string16 title = base::SysNSStringToUTF16([nameField_ stringValue]);
+  base::string16 title = base::SysNSStringToUTF16([nameField_ stringValue]);
   BOOL titleValid = controller_->IsTitleValid(title);
   [self setIsValid:titleValid
            toolTip:IDS_SEARCH_ENGINES_INVALID_TITLE_TT
       forImageView:nameImage_
          textField:nameField_];
 
-  string16 keyword = base::SysNSStringToUTF16([keywordField_ stringValue]);
+  base::string16 keyword =
+      base::SysNSStringToUTF16([keywordField_ stringValue]);
   BOOL keywordValid = controller_->IsKeywordValid(keyword);
   [self setIsValid:keywordValid
            toolTip:IDS_SEARCH_ENGINES_INVALID_KEYWORD_TT
diff --git a/chrome/browser/ui/cocoa/browser_window_cocoa.h b/chrome/browser/ui/cocoa/browser_window_cocoa.h
index 92f9e14..4091953 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.h
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.h
@@ -108,8 +108,8 @@ class BrowserWindowCocoa :
 #if defined(ENABLE_ONE_CLICK_SIGNIN)
   virtual void ShowOneClickSigninBubble(
       OneClickSigninBubbleType type,
-      const string16& email,
-      const string16& error_message,
+      const base::string16& email,
+      const base::string16& error_message,
       const StartSyncCallback& start_sync_callback) OVERRIDE;
 #endif
   virtual bool IsDownloadShelfVisible() const OVERRIDE;
diff --git a/chrome/browser/ui/cocoa/browser_window_cocoa.mm b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
index 5072ecc..982d068 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
@@ -488,8 +488,8 @@ void BrowserWindowCocoa::ShowTranslateBubble(
 #if defined(ENABLE_ONE_CLICK_SIGNIN)
 void BrowserWindowCocoa::ShowOneClickSigninBubble(
     OneClickSigninBubbleType type,
-    const string16& email,
-    const string16& error_message,
+    const base::string16& email,
+    const base::string16& error_message,
     const StartSyncCallback& start_sync_callback) {
   WebContents* web_contents =
         browser_->tab_strip_model()->GetActiveWebContents();
diff --git a/chrome/browser/ui/cocoa/browser_window_controller.mm b/chrome/browser/ui/cocoa/browser_window_controller.mm
index d9916d6..783c113 100644
--- a/chrome/browser/ui/cocoa/browser_window_controller.mm
+++ b/chrome/browser/ui/cocoa/browser_window_controller.mm
@@ -234,7 +234,7 @@ enum {
     }
   }
 
-  string16 label = signin_ui_util::GetSigninMenuLabel(profile);
+  base::string16 label = signin_ui_util::GetSigninMenuLabel(profile);
   [signinMenuItem setTitle:l10n_util::FixUpWindowsStyleLabel(label)];
   [signinMenuItem setHidden:!showSigninMenuItem];
   [followingSeparator setHidden:!showSigninMenuItem];
diff --git a/chrome/browser/ui/cocoa/content_settings/collected_cookies_mac.mm b/chrome/browser/ui/cocoa/content_settings/collected_cookies_mac.mm
index 389ad2c..11b581f 100644
--- a/chrome/browser/ui/cocoa/content_settings/collected_cookies_mac.mm
+++ b/chrome/browser/ui/cocoa/content_settings/collected_cookies_mac.mm
@@ -111,7 +111,7 @@ void CollectedCookiesMac::OnConstrainedWindowClosed(
 #pragma mark Window Controller
 
 @interface CollectedCookiesWindowController(Private)
--(void)showInfoBarForDomain:(const string16&)domain
+-(void)showInfoBarForDomain:(const base::string16&)domain
                     setting:(ContentSetting)setting;
 -(void)showInfoBarForMultipleDomainsAndSetting:(ContentSetting)setting;
 -(void)animateInfoBar;
@@ -230,7 +230,7 @@ void CollectedCookiesMac::OnConstrainedWindowClosed(
    forTreeController:(NSTreeController*)controller {
   NSArray* nodes = [controller selectedNodes];
   BOOL multipleDomainsChanged = NO;
-  string16 lastDomain;
+  base::string16 lastDomain;
   for (NSTreeNode* treeNode in nodes) {
     CocoaCookieTreeNode* node = [treeNode representedObject];
     CookieTreeNode* cookie = static_cast<CookieTreeNode*>([node treeNode]);
@@ -417,7 +417,7 @@ void CollectedCookiesMac::OnConstrainedWindowClosed(
   [self animateInfoBar];
 }
 
--(void)showInfoBarForDomain:(const string16&)domain
+-(void)showInfoBarForDomain:(const base::string16&)domain
                     setting:(ContentSetting)setting {
   NSString* label;
   switch (setting) {
diff --git a/chrome/browser/ui/cocoa/content_settings/cookie_details.h b/chrome/browser/ui/cocoa/content_settings/cookie_details.h
index c0c9c84..e76d0d1 100644
--- a/chrome/browser/ui/cocoa/content_settings/cookie_details.h
+++ b/chrome/browser/ui/cocoa/content_settings/cookie_details.h
@@ -177,8 +177,8 @@ enum CocoaCookieDetailsType {
 
 // Used for database details in the cookie prompt dialog.
 - (id)initWithDatabase:(const std::string&)domain
-          databaseName:(const string16&)databaseName
-   databaseDescription:(const string16&)databaseDescription
+          databaseName:(const base::string16&)databaseName
+   databaseDescription:(const base::string16&)databaseDescription
               fileSize:(unsigned long)fileSize;
 
 // -initWithAppCacheInfo: creates a cookie details with the manifest URL plus
@@ -188,8 +188,8 @@ enum CocoaCookieDetailsType {
 
 // Used for local storage details in the cookie prompt dialog.
 - (id)initWithLocalStorage:(const std::string&)domain
-                       key:(const string16&)key
-                     value:(const string16&)value;
+                       key:(const base::string16&)key
+                     value:(const base::string16&)value;
 
 // -initWithAppCacheManifestURL: is called when the cookie prompt is displayed
 // for an appcache, at that time only the manifest URL of the appcache is known.
diff --git a/chrome/browser/ui/cocoa/content_settings/cookie_details.mm b/chrome/browser/ui/cocoa/content_settings/cookie_details.mm
index 6cde051..02f6f57 100644
--- a/chrome/browser/ui/cocoa/content_settings/cookie_details.mm
+++ b/chrome/browser/ui/cocoa/content_settings/cookie_details.mm
@@ -201,8 +201,8 @@
 }
 
 - (id)initWithDatabase:(const std::string&)domain
-          databaseName:(const string16&)databaseName
-   databaseDescription:(const string16&)databaseDescription
+          databaseName:(const base::string16&)databaseName
+   databaseDescription:(const base::string16&)databaseDescription
               fileSize:(unsigned long)fileSize {
   if ((self = [super init])) {
     type_ = kCocoaCookieDetailsTypePromptDatabase;
@@ -218,8 +218,8 @@
 }
 
 - (id)initWithLocalStorage:(const std::string&)domain
-                       key:(const string16&)key
-                     value:(const string16&)value {
+                       key:(const base::string16&)key
+                     value:(const base::string16&)value {
   if ((self = [super init])) {
     type_ = kCocoaCookieDetailsTypePromptLocalStorage;
     canEditExpiration_ = NO;
diff --git a/chrome/browser/ui/cocoa/content_settings/cookie_details_unittest.mm b/chrome/browser/ui/cocoa/content_settings/cookie_details_unittest.mm
index a7761b1..3c9dc36 100644
--- a/chrome/browser/ui/cocoa/content_settings/cookie_details_unittest.mm
+++ b/chrome/browser/ui/cocoa/content_settings/cookie_details_unittest.mm
@@ -165,8 +165,8 @@ TEST_F(CookiesDetailsTest, CreateForTreeIndexedDB) {
 TEST_F(CookiesDetailsTest, CreateForPromptDatabase) {
   base::scoped_nsobject<CocoaCookieDetails> details;
   std::string domain("chromium.org");
-  string16 name(base::SysNSStringToUTF16(@"wicked_name"));
-  string16 desc(base::SysNSStringToUTF16(@"desc"));
+  base::string16 name(base::SysNSStringToUTF16(@"wicked_name"));
+  base::string16 desc(base::SysNSStringToUTF16(@"desc"));
   details.reset([[CocoaCookieDetails alloc] initWithDatabase:domain
                                                 databaseName:name
                                          databaseDescription:desc
@@ -191,8 +191,8 @@ TEST_F(CookiesDetailsTest, CreateForPromptDatabase) {
 TEST_F(CookiesDetailsTest, CreateForPromptLocalStorage) {
   base::scoped_nsobject<CocoaCookieDetails> details;
   std::string domain("chromium.org");
-  string16 key(base::SysNSStringToUTF16(@"testKey"));
-  string16 value(base::SysNSStringToUTF16(@"testValue"));
+  base::string16 key(base::SysNSStringToUTF16(@"testKey"));
+  base::string16 value(base::SysNSStringToUTF16(@"testValue"));
   details.reset([[CocoaCookieDetails alloc] initWithLocalStorage:domain
                                                              key:key
                                                            value:value]);
diff --git a/chrome/browser/ui/cocoa/content_settings/cookie_details_view_controller_unittest.mm b/chrome/browser/ui/cocoa/content_settings/cookie_details_view_controller_unittest.mm
index c901c71..789e64f 100644
--- a/chrome/browser/ui/cocoa/content_settings/cookie_details_view_controller_unittest.mm
+++ b/chrome/browser/ui/cocoa/content_settings/cookie_details_view_controller_unittest.mm
@@ -35,8 +35,8 @@ static CookiePromptContentDetailsAdapter* CreateCookieTestContent(
 
 static CocoaCookieDetails* CreateTestDatabaseDetails() {
   std::string domain("chromium.org");
-  string16 name(base::SysNSStringToUTF16(@"wicked_name"));
-  string16 desc(base::SysNSStringToUTF16(@"wicked_desc"));
+  base::string16 name(base::SysNSStringToUTF16(@"wicked_name"));
+  base::string16 desc(base::SysNSStringToUTF16(@"wicked_desc"));
   CocoaCookieDetails* details = [CocoaCookieDetails alloc];
   [details initWithDatabase:domain
                databaseName:name
diff --git a/chrome/browser/ui/cocoa/download/download_item_cell.mm b/chrome/browser/ui/cocoa/download/download_item_cell.mm
index bb18147..6f54fe0 100644
--- a/chrome/browser/ui/cocoa/download/download_item_cell.mm
+++ b/chrome/browser/ui/cocoa/download/download_item_cell.mm
@@ -185,7 +185,7 @@ using content::DownloadItem;
   // Set the name of the download.
   downloadPath_ = downloadModel->download()->GetFileNameToReportUser();
 
-  string16 statusText = downloadModel->GetStatusText();
+  base::string16 statusText = downloadModel->GetStatusText();
   if (statusText.empty()) {
     // Remove the status text label.
     [self hideSecondaryTitle];
diff --git a/chrome/browser/ui/cocoa/download/download_item_controller.mm b/chrome/browser/ui/cocoa/download/download_item_controller.mm
index f5e3cb5..5bc66cc 100644
--- a/chrome/browser/ui/cocoa/download/download_item_controller.mm
+++ b/chrome/browser/ui/cocoa/download/download_item_controller.mm
@@ -260,7 +260,7 @@ class DownloadShelfContextMenuMac : public DownloadShelfContextMenu {
 }
 
 - (void)updateToolTip {
-  string16 tooltip_text =
+  base::string16 tooltip_text =
       bridge_->download_model()->GetTooltipText(*font_list_, kToolTipMaxWidth);
   [progressView_ setToolTip:base::SysUTF16ToNSString(tooltip_text)];
 }
diff --git a/chrome/browser/ui/cocoa/external_protocol_dialog.mm b/chrome/browser/ui/cocoa/external_protocol_dialog.mm
index d4aacba..5525925 100644
--- a/chrome/browser/ui/cocoa/external_protocol_dialog.mm
+++ b/chrome/browser/ui/cocoa/external_protocol_dialog.mm
@@ -44,7 +44,7 @@ void ExternalProtocolHandler::RunExternalProtocolDialog(
   url_ = *url;
   creation_time_ = base::Time::Now();
 
-  string16 appName = [self appNameForProtocol];
+  base::string16 appName = [self appNameForProtocol];
   if (appName.length() == 0) {
     // No registered apps for this protocol; give up and go home.
     [self autorelease];
@@ -64,7 +64,7 @@ void ExternalProtocolHandler::RunExternalProtocolDialog(
         IDS_EXTERNAL_PROTOCOL_CANCEL_BUTTON_TEXT)];
 
   const int kMaxUrlWithoutSchemeSize = 256;
-  string16 elided_url_without_scheme;
+  base::string16 elided_url_without_scheme;
   gfx::ElideString(ASCIIToUTF16(url_.possibly_invalid_spec()),
                   kMaxUrlWithoutSchemeSize, &elided_url_without_scheme);
 
@@ -143,7 +143,7 @@ void ExternalProtocolHandler::RunExternalProtocolDialog(
                                            &openingApp);
   if (status != noErr) {
     // likely kLSApplicationNotFoundErr
-    return string16();
+    return base::string16();
   }
   NSString* appPath = [(NSURL*)openingApp path];
   CFRelease(openingApp);  // NOT A BUG; LSGetApplicationForURL retains for us
diff --git a/chrome/browser/ui/cocoa/global_error_bubble_controller.mm b/chrome/browser/ui/cocoa/global_error_bubble_controller.mm
index d053972..551abe9 100644
--- a/chrome/browser/ui/cocoa/global_error_bubble_controller.mm
+++ b/chrome/browser/ui/cocoa/global_error_bubble_controller.mm
@@ -88,7 +88,7 @@ class Bridge : public GlobalErrorBubbleViewBase {
 
   [title_ setStringValue:SysUTF16ToNSString(error_->GetBubbleViewTitle())];
   std::vector<string16> messages = error_->GetBubbleViewMessages();
-  string16 message = JoinString(messages, '\n');
+  base::string16 message = JoinString(messages, '\n');
 
   base::scoped_nsobject<NSMutableAttributedString> messageValue(
       [[NSMutableAttributedString alloc]
@@ -104,7 +104,7 @@ class Bridge : public GlobalErrorBubbleViewBase {
 
   [acceptButton_ setTitle:
       SysUTF16ToNSString(error_->GetBubbleViewAcceptButtonLabel())];
-  string16 cancelLabel = error_->GetBubbleViewCancelButtonLabel();
+  base::string16 cancelLabel = error_->GetBubbleViewCancelButtonLabel();
   if (cancelLabel.empty())
     [cancelButton_ setHidden:YES];
   else
diff --git a/chrome/browser/ui/cocoa/history_menu_bridge.h b/chrome/browser/ui/cocoa/history_menu_bridge.h
index 2ab76ed1..91e79af 100644
--- a/chrome/browser/ui/cocoa/history_menu_bridge.h
+++ b/chrome/browser/ui/cocoa/history_menu_bridge.h
@@ -71,7 +71,7 @@ class HistoryMenuBridge : public content::NotificationObserver,
     ~HistoryItem();
 
     // The title for the menu item.
-    string16 title;
+    base::string16 title;
     // The URL that will be navigated to if the user selects this item.
     GURL url;
     // Favicon for the URL.
diff --git a/chrome/browser/ui/cocoa/history_menu_bridge.mm b/chrome/browser/ui/cocoa/history_menu_bridge.mm
index d206e8e..1da19c9 100644
--- a/chrome/browser/ui/cocoa/history_menu_bridge.mm
+++ b/chrome/browser/ui/cocoa/history_menu_bridge.mm
@@ -349,7 +349,7 @@ NSMenuItem* HistoryMenuBridge::AddItemToMenu(HistoryItem* item,
     title = base::SysUTF8ToNSString(url_string);
   NSString* full_title = title;
   if ([title length] > kMaximumMenuWidthInChars) {
-    // TODO(rsesek): use app/text_elider.h once it uses string16 and can
+    // TODO(rsesek): use app/text_elider.h once it uses base::string16 and can
     // take out the middle of strings.
     title = [NSString stringWithFormat:@"%@…%@",
                [title substringToIndex:kMenuTrimSizeInChars],
@@ -402,7 +402,7 @@ void HistoryMenuBridge::CreateMenu() {
   options.SetRecentDayRange(kVisitedScope);
 
   history_service_->QueryHistory(
-      string16(),
+      base::string16(),
       options,
       &cancelable_request_consumer_,
       base::Bind(&HistoryMenuBridge::OnVisitedHistoryResults,
diff --git a/chrome/browser/ui/cocoa/history_menu_bridge_unittest.mm b/chrome/browser/ui/cocoa/history_menu_bridge_unittest.mm
index 12920f7..e5779ee 100644
--- a/chrome/browser/ui/cocoa/history_menu_bridge_unittest.mm
+++ b/chrome/browser/ui/cocoa/history_menu_bridge_unittest.mm
@@ -85,7 +85,7 @@ class HistoryMenuBridgeTest : public CocoaProfileTest {
     return item;
   }
 
-  HistoryMenuBridge::HistoryItem* CreateItem(const string16& title) {
+  HistoryMenuBridge::HistoryItem* CreateItem(const base::string16& title) {
     HistoryMenuBridge::HistoryItem* item =
         new HistoryMenuBridge::HistoryItem();
     item->title = title;
@@ -175,8 +175,8 @@ TEST_F(HistoryMenuBridgeTest, ClearHistoryMenuEmpty) {
 TEST_F(HistoryMenuBridgeTest, AddItemToMenu) {
   NSMenu* menu = [[[NSMenu alloc] initWithTitle:@"history foo"] autorelease];
 
-  const string16 short_url = ASCIIToUTF16("http://foo/");
-  const string16 long_url = ASCIIToUTF16("http://super-duper-long-url--."
+  const base::string16 short_url = ASCIIToUTF16("http://foo/");
+  const base::string16 long_url = ASCIIToUTF16("http://super-duper-long-url--."
       "that.cannot.possibly.fit.even-in-80-columns"
       "or.be.reasonably-displayed-in-a-menu"
       "without.looking-ridiculous.com/"); // 140 chars total
diff --git a/chrome/browser/ui/cocoa/hung_renderer_controller.mm b/chrome/browser/ui/cocoa/hung_renderer_controller.mm
index 01b1ef9..cf314dc 100644
--- a/chrome/browser/ui/cocoa/hung_renderer_controller.mm
+++ b/chrome/browser/ui/cocoa/hung_renderer_controller.mm
@@ -179,7 +179,7 @@ class WebContentsObserverBridge : public content::WebContentsObserver {
   base::scoped_nsobject<NSMutableArray> favicons([[NSMutableArray alloc] init]);
   for (TabContentsIterator it; !it.done(); it.Next()) {
     if (it->GetRenderProcessHost() == hungContents_->GetRenderProcessHost()) {
-      string16 title = it->GetTitle();
+      base::string16 title = it->GetTitle();
       if (title.empty())
         title = CoreTabHelper::GetDefaultTitle();
       [titles addObject:base::SysUTF16ToNSString(title)];
diff --git a/chrome/browser/ui/cocoa/infobars/alternate_nav_infobar_controller.mm b/chrome/browser/ui/cocoa/infobars/alternate_nav_infobar_controller.mm
index 3d0be70..6a7585f 100644
--- a/chrome/browser/ui/cocoa/infobars/alternate_nav_infobar_controller.mm
+++ b/chrome/browser/ui/cocoa/infobars/alternate_nav_infobar_controller.mm
@@ -27,9 +27,9 @@
   AlternateNavInfoBarDelegate* delegate =
       static_cast<AlternateNavInfoBarDelegate*>([self delegate]);
   DCHECK(delegate);
-  size_t offset = string16::npos;
-  string16 message = delegate->GetMessageTextWithOffset(&offset);
-  string16 link = delegate->GetLinkText();
+  size_t offset = base::string16::npos;
+  base::string16 message = delegate->GetMessageTextWithOffset(&offset);
+  base::string16 link = delegate->GetLinkText();
   NSFont* font = [NSFont labelFontOfSize:
                   [NSFont systemFontSizeForControlSize:NSRegularControlSize]];
   HyperlinkTextView* view = (HyperlinkTextView*)label_.get();
diff --git a/chrome/browser/ui/cocoa/infobars/before_translate_infobar_controller.mm b/chrome/browser/ui/cocoa/infobars/before_translate_infobar_controller.mm
index fb1af15..cec81f5 100644
--- a/chrome/browser/ui/cocoa/infobars/before_translate_infobar_controller.mm
+++ b/chrome/browser/ui/cocoa/infobars/before_translate_infobar_controller.mm
@@ -15,8 +15,8 @@ using InfoBarUtilities::VerifyControlOrderAndSpacing;
 namespace {
 
 NSButton* CreateNSButtonWithResourceIDAndParameter(
-    int resourceId, const string16& param) {
-  string16 title = l10n_util::GetStringFUTF16(resourceId, param);
+    int resourceId, const base::string16& param) {
+  base::string16 title = l10n_util::GetStringFUTF16(resourceId, param);
   NSButton* button = [[NSButton alloc] init];
   [button setTitle:base::SysUTF16ToNSString(title)];
   [button setBezelStyle:NSTexturedRoundedBezelStyle];
@@ -46,7 +46,7 @@ NSButton* CreateNSButtonWithResourceIDAndParameter(
 
 - (void)initializeExtraControls {
   TranslateInfoBarDelegate* delegate = [self delegate];
-  const string16& language =
+  const base::string16& language =
       delegate->language_name_at(delegate->original_language_index());
   neverTranslateButton_.reset(
       CreateNSButtonWithResourceIDAndParameter(
@@ -80,9 +80,9 @@ NSButton* CreateNSButtonWithResourceIDAndParameter(
 
 - (void)loadLabelText {
   size_t offset = 0;
-  string16 text =
+  base::string16 text =
       l10n_util::GetStringFUTF16(IDS_TRANSLATE_INFOBAR_BEFORE_MESSAGE,
-                                 string16(), &offset);
+                                 base::string16(), &offset);
   NSString* string1 = base::SysUTF16ToNSString(text.substr(0, offset));
   NSString* string2 = base::SysUTF16ToNSString(text.substr(offset));
   [label1_ setStringValue:string1];
diff --git a/chrome/browser/ui/cocoa/infobars/confirm_infobar_controller.mm b/chrome/browser/ui/cocoa/infobars/confirm_infobar_controller.mm
index 99c34bb..4a771ac 100644
--- a/chrome/browser/ui/cocoa/infobars/confirm_infobar_controller.mm
+++ b/chrome/browser/ui/cocoa/infobars/confirm_infobar_controller.mm
@@ -107,7 +107,7 @@
 
   // Set the text and link.
   NSString* message = base::SysUTF16ToNSString(delegate->GetMessageText());
-  string16 link = delegate->GetLinkText();
+  base::string16 link = delegate->GetLinkText();
   if (!link.empty()) {
     // Add spacing between the label and the link.
     message = [message stringByAppendingString:@"   "];
diff --git a/chrome/browser/ui/cocoa/infobars/mock_confirm_infobar_delegate.cc b/chrome/browser/ui/cocoa/infobars/mock_confirm_infobar_delegate.cc
index f772168..7686a26 100644
--- a/chrome/browser/ui/cocoa/infobars/mock_confirm_infobar_delegate.cc
+++ b/chrome/browser/ui/cocoa/infobars/mock_confirm_infobar_delegate.cc
@@ -52,7 +52,7 @@ bool MockConfirmInfoBarDelegate::Cancel() {
 
 string16 MockConfirmInfoBarDelegate::GetLinkText() const {
   link_text_accessed_ = true;
-  return string16();
+  return base::string16();
 }
 
 bool MockConfirmInfoBarDelegate::LinkClicked(
diff --git a/chrome/browser/ui/cocoa/infobars/mock_confirm_infobar_delegate.h b/chrome/browser/ui/cocoa/infobars/mock_confirm_infobar_delegate.h
index 4df1112..1051b1a 100644
--- a/chrome/browser/ui/cocoa/infobars/mock_confirm_infobar_delegate.h
+++ b/chrome/browser/ui/cocoa/infobars/mock_confirm_infobar_delegate.h
@@ -37,11 +37,11 @@ class MockConfirmInfoBarDelegate : public ConfirmInfoBarDelegate {
  private:
   // ConfirmInfoBarDelegate:
   virtual int GetIconID() const OVERRIDE;
-  virtual string16 GetMessageText() const OVERRIDE;
-  virtual string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
   virtual bool Accept() OVERRIDE;
   virtual bool Cancel() OVERRIDE;
-  virtual string16 GetLinkText() const OVERRIDE;
+  virtual base::string16 GetLinkText() const OVERRIDE;
   virtual bool LinkClicked(WindowOpenDisposition disposition) OVERRIDE;
 
   Owner* owner_;
diff --git a/chrome/browser/ui/cocoa/infobars/translate_message_infobar_controller.mm b/chrome/browser/ui/cocoa/infobars/translate_message_infobar_controller.mm
index d210d21..53e0a61 100644
--- a/chrome/browser/ui/cocoa/infobars/translate_message_infobar_controller.mm
+++ b/chrome/browser/ui/cocoa/infobars/translate_message_infobar_controller.mm
@@ -17,7 +17,7 @@ using InfoBarUtilities::MoveControl;
       label1_, translateMessageButton_, spaceBetweenControls_ * 2, true);
   TranslateInfoBarDelegate* delegate = [self delegate];
   if ([self delegate]->ShouldShowMessageInfoBarButton()) {
-    string16 buttonText = delegate->GetMessageInfoBarButtonText();
+    base::string16 buttonText = delegate->GetMessageInfoBarButtonText();
     [translateMessageButton_ setTitle:base::SysUTF16ToNSString(buttonText)];
     [translateMessageButton_ sizeToFit];
   }
@@ -37,7 +37,7 @@ using InfoBarUtilities::MoveControl;
 
 - (void)loadLabelText {
   TranslateInfoBarDelegate* delegate = [self delegate];
-  string16 messageText = delegate->GetMessageInfoBarText();
+  base::string16 messageText = delegate->GetMessageInfoBarText();
   NSString* string1 = base::SysUTF16ToNSString(messageText);
   [label1_ setStringValue:string1];
 }
diff --git a/chrome/browser/ui/cocoa/keystone_infobar_delegate.mm b/chrome/browser/ui/cocoa/keystone_infobar_delegate.mm
index b25ab67..8641d26 100644
--- a/chrome/browser/ui/cocoa/keystone_infobar_delegate.mm
+++ b/chrome/browser/ui/cocoa/keystone_infobar_delegate.mm
@@ -53,8 +53,8 @@ class KeystonePromotionInfoBarDelegate : public ConfirmInfoBarDelegate {
 
   // ConfirmInfoBarDelegate
   virtual int GetIconID() const OVERRIDE;
-  virtual string16 GetMessageText() const OVERRIDE;
-  virtual string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
   virtual bool Accept() OVERRIDE;
   virtual bool Cancel() OVERRIDE;
   virtual bool ShouldExpireInternal(
diff --git a/chrome/browser/ui/cocoa/location_bar/keyword_hint_decoration.h b/chrome/browser/ui/cocoa/location_bar/keyword_hint_decoration.h
index cd218e8..0342bc3 100644
--- a/chrome/browser/ui/cocoa/location_bar/keyword_hint_decoration.h
+++ b/chrome/browser/ui/cocoa/location_bar/keyword_hint_decoration.h
@@ -21,7 +21,7 @@ class KeywordHintDecoration : public LocationBarDecoration {
 
   // Calculates the message to display and where to place the [tab]
   // image.
-  void SetKeyword(const string16& keyword, bool is_extension_keyword);
+  void SetKeyword(const base::string16& keyword, bool is_extension_keyword);
 
   // Implement |LocationBarDecoration|.
   virtual void DrawInFrame(NSRect frame, NSView* control_view) OVERRIDE;
diff --git a/chrome/browser/ui/cocoa/location_bar/keyword_hint_decoration.mm b/chrome/browser/ui/cocoa/location_bar/keyword_hint_decoration.mm
index 340f7e4..f8fb800 100644
--- a/chrome/browser/ui/cocoa/location_bar/keyword_hint_decoration.mm
+++ b/chrome/browser/ui/cocoa/location_bar/keyword_hint_decoration.mm
@@ -30,8 +30,8 @@ const CGFloat kHintAvailableRatio = 2.0 / 3.0;
 
 // Helper to convert |s| to an |NSString|, trimming whitespace at
 // ends.
-NSString* TrimAndConvert(const string16& s) {
-  string16 output;
+NSString* TrimAndConvert(const base::string16& s) {
+  base::string16 output;
   TrimWhitespace(s, TRIM_ALL, &output);
   return base::SysUTF16ToNSString(output);
 }
@@ -56,7 +56,7 @@ NSImage* KeywordHintDecoration::GetHintImage() {
   return hint_image_;
 }
 
-void KeywordHintDecoration::SetKeyword(const string16& short_name,
+void KeywordHintDecoration::SetKeyword(const base::string16& short_name,
                                        bool is_extension_keyword) {
   // KEYWORD_HINT is a message like "Press [tab] to search <site>".
   // [tab] is a parameter to be replaced by an image.  "<site>" is
@@ -64,9 +64,9 @@ void KeywordHintDecoration::SetKeyword(const string16& short_name,
   std::vector<size_t> content_param_offsets;
   int message_id = is_extension_keyword ?
       IDS_OMNIBOX_EXTENSION_KEYWORD_HINT : IDS_OMNIBOX_KEYWORD_HINT;
-  const string16 keyword_hint(
+  const base::string16 keyword_hint(
       l10n_util::GetStringFUTF16(message_id,
-                                 string16(), short_name,
+                                 base::string16(), short_name,
                                  &content_param_offsets));
 
   // Should always be 2 offsets, see the comment in
diff --git a/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h b/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h
index c856b5f..ba11001 100644
--- a/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h
+++ b/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h
@@ -143,7 +143,7 @@ class LocationBarViewMac : public LocationBar,
   virtual ToolbarModel* GetToolbarModel() OVERRIDE;
   virtual const ToolbarModel* GetToolbarModel() const OVERRIDE;
 
-  NSImage* GetKeywordImage(const string16& keyword);
+  NSImage* GetKeywordImage(const base::string16& keyword);
 
   AutocompleteTextField* GetAutocompleteTextField() { return field_; }
 
diff --git a/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.mm b/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.mm
index 4d2457a..e51ae5a 100644
--- a/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.mm
+++ b/chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.mm
@@ -384,8 +384,8 @@ void LocationBarViewMac::Layout() {
   keyword_hint_decoration_->SetVisible(false);
 
   // Get the keyword to use for keyword-search and hinting.
-  const string16 keyword = omnibox_view_->model()->keyword();
-  string16 short_name;
+  const base::string16 keyword = omnibox_view_->model()->keyword();
+  base::string16 short_name;
   bool is_extension_keyword = false;
   if (!keyword.empty()) {
     short_name = TemplateURLServiceFactory::GetForProfile(profile_)->
@@ -405,7 +405,7 @@ void LocationBarViewMac::Layout() {
     location_icon_decoration_->SetVisible(false);
     ev_bubble_decoration_->SetVisible(true);
 
-    string16 label(GetToolbarModel()->GetEVCertName());
+    base::string16 label(GetToolbarModel()->GetEVCertName());
     ev_bubble_decoration_->SetFullLabel(base::SysUTF16ToNSString(label));
   } else if (!keyword.empty() && is_keyword_hint) {
     keyword_hint_decoration_->SetKeyword(short_name,
@@ -544,7 +544,7 @@ const ToolbarModel* LocationBarViewMac::GetToolbarModel() const {
   return browser_->toolbar_model();
 }
 
-NSImage* LocationBarViewMac::GetKeywordImage(const string16& keyword) {
+NSImage* LocationBarViewMac::GetKeywordImage(const base::string16& keyword) {
   const TemplateURL* template_url = TemplateURLServiceFactory::GetForProfile(
       profile_)->GetTemplateURLForKeyword(keyword);
   if (template_url &&
diff --git a/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration.h b/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration.h
index 96b6d13..9c6abf1 100644
--- a/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration.h
+++ b/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration.h
@@ -19,7 +19,7 @@ class SelectedKeywordDecoration : public BubbleDecoration {
 
   // Calculates appropriate full and partial label strings based on
   // inputs.
-  void SetKeyword(const string16& keyword, bool is_extension_keyword);
+  void SetKeyword(const base::string16& keyword, bool is_extension_keyword);
 
   // Determines what combination of labels and image will best fit
   // within |width|, makes those current for |BubbleDecoration|, and
diff --git a/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration.mm b/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration.mm
index e7d654f..a19a477 100644
--- a/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration.mm
+++ b/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration.mm
@@ -53,9 +53,10 @@ ui::NinePartImageIds SelectedKeywordDecoration::GetBubbleImageIds() {
   };
 }
 
-void SelectedKeywordDecoration::SetKeyword(const string16& short_name,
+void SelectedKeywordDecoration::SetKeyword(const base::string16& short_name,
                                            bool is_extension_keyword) {
-  const string16 min_name(location_bar_util::CalculateMinString(short_name));
+  const base::string16 min_name(
+      location_bar_util::CalculateMinString(short_name));
   NSString* full_string = is_extension_keyword ?
       base::SysUTF16ToNSString(short_name) :
       l10n_util::GetNSStringF(IDS_OMNIBOX_KEYWORD_TEXT, short_name);
diff --git a/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration_unittest.mm b/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration_unittest.mm
index 3c5ab03..e850e9d 100644
--- a/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration_unittest.mm
+++ b/chrome/browser/ui/cocoa/location_bar/selected_keyword_decoration_unittest.mm
@@ -32,7 +32,7 @@ class SelectedKeywordDecorationTest : public CocoaTest {
 // not enough room.
 TEST_F(SelectedKeywordDecorationTest, UsesPartialKeywordIfNarrow) {
 
-  const string16 kKeyword = ASCIIToUTF16("Engine");
+  const base::string16 kKeyword = ASCIIToUTF16("Engine");
   NSString* const kFullString = @"Search Engine:";
   NSString* const kPartialString = @"Search En\u2026:";  // ellipses
 
diff --git a/chrome/browser/ui/cocoa/location_bar/zoom_decoration.mm b/chrome/browser/ui/cocoa/location_bar/zoom_decoration.mm
index 912b17d..0caa1d9 100644
--- a/chrome/browser/ui/cocoa/location_bar/zoom_decoration.mm
+++ b/chrome/browser/ui/cocoa/location_bar/zoom_decoration.mm
@@ -34,7 +34,8 @@ void ZoomDecoration::Update(ZoomController* zoom_controller) {
   SetImage(OmniboxViewMac::ImageForResource(
       zoom_controller->GetResourceForZoomLevel()));
 
-  string16 zoom_percent = base::IntToString16(zoom_controller->zoom_percent());
+  base::string16 zoom_percent =
+      base::IntToString16(zoom_controller->zoom_percent());
   NSString* zoom_string =
       l10n_util::GetNSStringFWithFixup(IDS_TOOLTIP_ZOOM, zoom_percent);
   tooltip_.reset([zoom_string retain]);
diff --git a/chrome/browser/ui/cocoa/login_prompt_cocoa.mm b/chrome/browser/ui/cocoa/login_prompt_cocoa.mm
index b9a81d4..0b0572a 100644
--- a/chrome/browser/ui/cocoa/login_prompt_cocoa.mm
+++ b/chrome/browser/ui/cocoa/login_prompt_cocoa.mm
@@ -43,8 +43,9 @@ class LoginHandlerMac : public LoginHandler,
   }
 
   // LoginModelObserver implementation.
-  virtual void OnAutofillDataAvailable(const string16& username,
-                                       const string16& password) OVERRIDE {
+  virtual void OnAutofillDataAvailable(
+      const base::string16& username,
+      const base::string16& password) OVERRIDE {
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
     [sheet_controller_ autofillLogin:base::SysUTF16ToNSString(username)
@@ -55,7 +56,7 @@ class LoginHandlerMac : public LoginHandler,
   // LoginHandler:
   virtual void BuildViewForPasswordManager(
       PasswordManager* manager,
-      const string16& explanation) OVERRIDE {
+      const base::string16& explanation) OVERRIDE {
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
     sheet_controller_.reset(
@@ -99,8 +100,8 @@ class LoginHandlerMac : public LoginHandler,
     sheet_controller_.reset();
   }
 
-  void OnLoginPressed(const string16& username,
-                      const string16& password) {
+  void OnLoginPressed(const base::string16& username,
+                      const base::string16& password) {
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
     SetAuth(username, password);
   }
diff --git a/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_cocoa.h b/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_cocoa.h
index 62afc09..5ca332a 100644
--- a/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_cocoa.h
+++ b/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_cocoa.h
@@ -19,7 +19,7 @@ class DesktopMediaPickerCocoa : public DesktopMediaPicker {
   // Overridden from DesktopMediaPicker:
   virtual void Show(gfx::NativeWindow context,
                     gfx::NativeWindow parent,
-                    const string16& app_name,
+                    const base::string16& app_name,
                     scoped_ptr<DesktopMediaList> media_list,
                     const DoneCallback& done_callback) OVERRIDE;
 
diff --git a/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_cocoa.mm b/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_cocoa.mm
index 1b31516..57d3b32 100644
--- a/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_cocoa.mm
+++ b/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_cocoa.mm
@@ -14,7 +14,7 @@ DesktopMediaPickerCocoa::~DesktopMediaPickerCocoa() {
 
 void DesktopMediaPickerCocoa::Show(gfx::NativeWindow context,
                                    gfx::NativeWindow parent,
-                                   const string16& app_name,
+                                   const base::string16& app_name,
                                    scoped_ptr<DesktopMediaList> media_list,
                                    const DoneCallback& done_callback) {
   controller_.reset(
diff --git a/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_controller.h b/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_controller.h
index 4ad9883c..0d37bfe8 100644
--- a/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_controller.h
+++ b/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_controller.h
@@ -55,7 +55,7 @@
 // |appName| will be used to format the dialog's title and the label.
 - (id)initWithMediaList:(scoped_ptr<DesktopMediaList>)media_list
                callback:(const DesktopMediaPicker::DoneCallback&)callback
-                appName:(const string16&)appName;
+                appName:(const base::string16&)appName;
 
 @end
 
diff --git a/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_controller.mm b/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_controller.mm
index 31342a6..fb16902 100644
--- a/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_controller.mm
+++ b/chrome/browser/ui/cocoa/media_picker/desktop_media_picker_controller.mm
@@ -32,7 +32,7 @@ const int kExcessButtonPadding = 6;
 @interface DesktopMediaPickerController (Private)
 
 // Populate the window with controls and views.
-- (void)initializeContentsWithAppName:(const string16&)appName;
+- (void)initializeContentsWithAppName:(const base::string16&)appName;
 
 // Create a |NSTextField| with label traits given |width|. Frame height is
 // automatically adjusted to fit.
@@ -56,7 +56,7 @@ const int kExcessButtonPadding = 6;
 
 - (id)initWithMediaList:(scoped_ptr<DesktopMediaList>)media_list
                callback:(const DesktopMediaPicker::DoneCallback&)callback
-                appName:(const string16&)appName {
+                appName:(const base::string16&)appName {
   const NSUInteger kStyleMask =
       NSTitledWindowMask | NSClosableWindowMask | NSResizableWindowMask;
   base::scoped_nsobject<NSWindow> window(
@@ -83,7 +83,7 @@ const int kExcessButtonPadding = 6;
   [super dealloc];
 }
 
-- (void)initializeContentsWithAppName:(const string16&)appName {
+- (void)initializeContentsWithAppName:(const base::string16&)appName {
   // Use flipped coordinates to facilitate manual layout.
   const CGFloat kPaddedWidth = kInitialContentWidth - (kFramePadding * 2);
   base::scoped_nsobject<FlippedView> content(
diff --git a/chrome/browser/ui/cocoa/notifications/balloon_controller_unittest.mm b/chrome/browser/ui/cocoa/notifications/balloon_controller_unittest.mm
index b8f8137..6dfea68 100644
--- a/chrome/browser/ui/cocoa/notifications/balloon_controller_unittest.mm
+++ b/chrome/browser/ui/cocoa/notifications/balloon_controller_unittest.mm
@@ -79,7 +79,7 @@ class BalloonControllerTest : public ChromeRenderViewHostTestHarness {
 
 TEST_F(BalloonControllerTest, ShowAndCloseTest) {
   Notification n(GURL("http://www.google.com"), GURL("http://www.google.com"),
-      ASCIIToUTF16("http://www.google.com"), string16(),
+      ASCIIToUTF16("http://www.google.com"), base::string16(),
       new NotificationObjectProxy(-1, -1, -1, false));
   scoped_ptr<Balloon> balloon(
       new Balloon(n, profile(), collection_.get()));
@@ -95,7 +95,7 @@ TEST_F(BalloonControllerTest, ShowAndCloseTest) {
 
 TEST_F(BalloonControllerTest, SizesTest) {
   Notification n(GURL("http://www.google.com"), GURL("http://www.google.com"),
-      ASCIIToUTF16("http://www.google.com"), string16(),
+      ASCIIToUTF16("http://www.google.com"), base::string16(),
       new NotificationObjectProxy(-1, -1, -1, false));
   scoped_ptr<Balloon> balloon(
       new Balloon(n, profile(), collection_.get()));
diff --git a/chrome/browser/ui/cocoa/notifications/message_center_tray_bridge.mm b/chrome/browser/ui/cocoa/notifications/message_center_tray_bridge.mm
index acb9edc..b266e8c 100644
--- a/chrome/browser/ui/cocoa/notifications/message_center_tray_bridge.mm
+++ b/chrome/browser/ui/cocoa/notifications/message_center_tray_bridge.mm
@@ -100,7 +100,7 @@ void MessageCenterTrayBridge::UpdateStatusItem() {
   [status_item_view_ setUnreadCount:unread_count withQuietMode:quiet_mode];
 
   if (unread_count > 0) {
-    string16 unread_count_string = base::FormatNumber(unread_count);
+    base::string16 unread_count_string = base::FormatNumber(unread_count);
     [status_item_view_ setToolTip:
         l10n_util::GetNSStringF(IDS_MESSAGE_CENTER_TOOLTIP_UNREAD,
             unread_count_string)];
diff --git a/chrome/browser/ui/cocoa/notifications/message_center_tray_bridge_unittest.mm b/chrome/browser/ui/cocoa/notifications/message_center_tray_bridge_unittest.mm
index e8755f7..62cabb8 100644
--- a/chrome/browser/ui/cocoa/notifications/message_center_tray_bridge_unittest.mm
+++ b/chrome/browser/ui/cocoa/notifications/message_center_tray_bridge_unittest.mm
@@ -50,7 +50,7 @@ TEST_F(MessageCenterTrayBridgeTest, StatusItemOnlyAfterFirstNotification) {
           ASCIIToUTF16("First notification"),
           ASCIIToUTF16("This is a simple test."),
           gfx::Image(),
-          string16(),
+          base::string16(),
           message_center::NotifierId(),
           data,
           NULL));
diff --git a/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.h b/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.h
index da3b545..c14872b 100644
--- a/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.h
+++ b/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.h
@@ -60,7 +60,7 @@ class OmniboxPopupViewMac : public OmniboxPopupView,
   // Applies the given font and colors to the match string based on
   // classifications.
   static NSMutableAttributedString* DecorateMatchedString(
-      const string16& match_string,
+      const base::string16& match_string,
       const AutocompleteMatch::ACMatchClassifications& classifications,
       NSColor* text_color,
       NSColor* dim_text_color,
@@ -74,7 +74,7 @@ class OmniboxPopupViewMac : public OmniboxPopupView,
   // cleaner.
   static NSMutableAttributedString* ElideString(
       NSMutableAttributedString* a_string,
-      const string16& original_string,
+      const base::string16& original_string,
       const gfx::Font& font,
       const float cell_width);
 
diff --git a/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.mm b/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.mm
index d1f302b..17678d2 100644
--- a/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.mm
+++ b/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac.mm
@@ -246,7 +246,7 @@ NSAttributedString* OmniboxPopupViewMac::MatchText(
 
 // static
 NSMutableAttributedString* OmniboxPopupViewMac::DecorateMatchedString(
-    const string16& match_string,
+    const base::string16& match_string,
     const AutocompleteMatch::ACMatchClassifications& classifications,
     NSColor* text_color,
     NSColor* dim_text_color,
@@ -311,7 +311,7 @@ NSMutableAttributedString* OmniboxPopupViewMac::DecorateMatchedString(
 
 NSMutableAttributedString* OmniboxPopupViewMac::ElideString(
     NSMutableAttributedString* a_string,
-    const string16& original_string,
+    const base::string16& original_string,
     const gfx::Font& font,
     const float width) {
   // If it already fits, nothing to be done.
@@ -320,7 +320,7 @@ NSMutableAttributedString* OmniboxPopupViewMac::ElideString(
   }
 
   // If ElideText() decides to do nothing, nothing to be done.
-  const string16 elided =
+  const base::string16 elided =
       gfx::ElideText(original_string, font, width, gfx::ELIDE_AT_END);
   if (0 == elided.compare(original_string)) {
     return a_string;
diff --git a/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac_unittest.mm b/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac_unittest.mm
index 0b267de..062f0f5 100644
--- a/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac_unittest.mm
+++ b/chrome/browser/ui/cocoa/omnibox/omnibox_popup_view_mac_unittest.mm
@@ -76,8 +76,8 @@ bool RunHasFontTrait(NSAttributedString* string,
 
 // AutocompleteMatch doesn't really have the right constructor for our
 // needs.  Fake one for us to use.
-AutocompleteMatch MakeMatch(const string16& contents,
-                            const string16& description) {
+AutocompleteMatch MakeMatch(const base::string16& contents,
+                            const base::string16& description) {
   AutocompleteMatch m(NULL, 1, true, AutocompleteMatchType::URL_WHAT_YOU_TYPED);
   m.contents = contents;
   m.description = description;
@@ -373,7 +373,7 @@ TEST_F(OmniboxPopupViewMacTest, MatchTextContentsMatch) {
   EXPECT_EQ(run_length_1 + run_length_2 + run_length_3, [contents length]);
 
   AutocompleteMatch m = MakeMatch(base::SysNSStringToUTF16(contents),
-                                  string16());
+                                  base::string16());
 
   // Push each run onto contents classifications.
   m.contents_class.push_back(
@@ -467,7 +467,7 @@ TEST_F(OmniboxPopupViewMacTest, MatchTextDescriptionMatch) {
 
 TEST_F(OmniboxPopupViewMacTest, ElideString) {
   NSString* const contents = @"This is a test with long contents";
-  const string16 contents16(base::SysNSStringToUTF16(contents));
+  const base::string16 contents16(base::SysNSStringToUTF16(contents));
 
   const float kWide = 1000.0;
   const float kNarrow = 20.0;
@@ -487,7 +487,7 @@ TEST_F(OmniboxPopupViewMacTest, ElideString) {
 
   // When elided, result is the same as ElideText().
   ret = OmniboxPopupViewMac::ElideString(as, contents16, font_, kNarrow);
-  string16 elided =
+  base::string16 elided =
       gfx::ElideText(contents16, font_, kNarrow, gfx::ELIDE_AT_END);
   EXPECT_TRUE(ret == as);
   EXPECT_FALSE([[as string] isEqualToString:contents]);
diff --git a/chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.h b/chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.h
index b76cba2..becf719 100644
--- a/chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.h
+++ b/chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.h
@@ -32,16 +32,17 @@ class OmniboxViewMac : public OmniboxView,
   virtual void SaveStateToTab(content::WebContents* tab) OVERRIDE;
   virtual void OnTabChanged(const content::WebContents* web_contents) OVERRIDE;
   virtual void Update() OVERRIDE;
-  virtual string16 GetText() const OVERRIDE;
-  virtual void SetWindowTextAndCaretPos(const string16& text,
+  virtual base::string16 GetText() const OVERRIDE;
+  virtual void SetWindowTextAndCaretPos(const base::string16& text,
                                         size_t caret_pos,
                                         bool update_popup,
                                         bool notify_text_changed) OVERRIDE;
   virtual void SetForcedQuery() OVERRIDE;
   virtual bool IsSelectAll() const OVERRIDE;
   virtual bool DeleteAtEndPressed() OVERRIDE;
-  virtual void GetSelectionBounds(string16::size_type* start,
-                                  string16::size_type* end) const OVERRIDE;
+  virtual void GetSelectionBounds(
+      base::string16::size_type* start,
+      base::string16::size_type* end) const OVERRIDE;
   virtual void SelectAll(bool reversed) OVERRIDE;
   virtual void RevertAll() OVERRIDE;
   virtual void UpdatePopup() OVERRIDE;
@@ -49,19 +50,19 @@ class OmniboxViewMac : public OmniboxView,
   virtual void SetFocus() OVERRIDE;
   virtual void ApplyCaretVisibility() OVERRIDE;
   virtual void OnTemporaryTextMaybeChanged(
-      const string16& display_text,
+      const base::string16& display_text,
       bool save_original_selection,
       bool notify_text_changed) OVERRIDE;
   virtual bool OnInlineAutocompleteTextMaybeChanged(
-      const string16& display_text, size_t user_text_length) OVERRIDE;
+      const base::string16& display_text, size_t user_text_length) OVERRIDE;
   virtual void OnInlineAutocompleteTextCleared() OVERRIDE;
   virtual void OnRevertTemporaryText() OVERRIDE;
   virtual void OnBeforePossibleChange() OVERRIDE;
   virtual bool OnAfterPossibleChange() OVERRIDE;
   virtual gfx::NativeView GetNativeView() const OVERRIDE;
   virtual gfx::NativeView GetRelativeWindowForPopup() const OVERRIDE;
-  virtual void SetGrayTextAutocompletion(const string16& input) OVERRIDE;
-  virtual string16 GetGrayTextAutocompletion() const OVERRIDE;
+  virtual void SetGrayTextAutocompletion(const base::string16& input) OVERRIDE;
+  virtual base::string16 GetGrayTextAutocompletion() const OVERRIDE;
   virtual int TextWidth() const OVERRIDE;
   virtual bool IsImeComposing() const OVERRIDE;
 
@@ -131,14 +132,14 @@ class OmniboxViewMac : public OmniboxView,
 
   // Update the field with |display_text| and highlight the host and scheme (if
   // it's an URL or URL-fragment).  Resets any suggest text that may be present.
-  void SetText(const string16& display_text);
+  void SetText(const base::string16& display_text);
 
   // Internal implementation of SetText.  Does not reset the suggest text before
   // setting the display text.  Most callers should use |SetText()| instead.
-  void SetTextInternal(const string16& display_text);
+  void SetTextInternal(const base::string16& display_text);
 
   // Update the field with |display_text| and set the selection.
-  void SetTextAndSelectedRange(const string16& display_text,
+  void SetTextAndSelectedRange(const base::string16& display_text,
                                const NSRange range);
 
   // Pass the current content of |field_| to SetText(), maintaining
@@ -148,7 +149,7 @@ class OmniboxViewMac : public OmniboxView,
 
   // Calculates text attributes according to |display_text| and applies them
   // to the given |as| object.
-  void ApplyTextAttributes(const string16& display_text,
+  void ApplyTextAttributes(const base::string16& display_text,
                            NSMutableAttributedString* as);
 
   // Return the number of UTF-16 units in the current buffer, excluding the
@@ -170,7 +171,7 @@ class OmniboxViewMac : public OmniboxView,
   // Tracking state before and after a possible change for reporting
   // to model_.
   NSRange selection_before_change_;
-  string16 text_before_change_;
+  base::string16 text_before_change_;
   NSRange marked_range_before_change_;
 
   // Was delete pressed?
@@ -179,7 +180,7 @@ class OmniboxViewMac : public OmniboxView,
   // Was the delete key pressed with an empty selection at the end of the edit?
   bool delete_at_end_pressed_;
 
-  string16 suggest_text_;
+  base::string16 suggest_text_;
 
   DISALLOW_COPY_AND_ASSIGN(OmniboxViewMac);
 };
diff --git a/chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.mm b/chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.mm
index 4a5a333..932da71 100644
--- a/chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.mm
+++ b/chrome/browser/ui/cocoa/omnibox/omnibox_view_mac.mm
@@ -224,7 +224,7 @@ void OmniboxViewMac::Update() {
   }
 }
 
-string16 OmniboxViewMac::GetText() const {
+base::string16 OmniboxViewMac::GetText() const {
   return base::SysNSStringToUTF16([field_ stringValue]);
 }
 
@@ -255,7 +255,7 @@ void OmniboxViewMac::SetSelectedRange(const NSRange range) {
   }
 }
 
-void OmniboxViewMac::SetWindowTextAndCaretPos(const string16& text,
+void OmniboxViewMac::SetWindowTextAndCaretPos(const base::string16& text,
                                               size_t caret_pos,
                                               bool update_popup,
                                               bool notify_text_changed) {
@@ -275,7 +275,7 @@ void OmniboxViewMac::SetForcedQuery() {
 
   const base::string16 current_text(GetText());
   const size_t start = current_text.find_first_not_of(base::kWhitespaceUTF16);
-  if (start == string16::npos || (current_text[start] != '?')) {
+  if (start == base::string16::npos || (current_text[start] != '?')) {
     SetUserText(ASCIIToUTF16("?"));
   } else {
     NSRange range = NSMakeRange(start + 1, current_text.size() - start - 1);
@@ -294,8 +294,8 @@ bool OmniboxViewMac::DeleteAtEndPressed() {
   return delete_at_end_pressed_;
 }
 
-void OmniboxViewMac::GetSelectionBounds(string16::size_type* start,
-                                        string16::size_type* end) const {
+void OmniboxViewMac::GetSelectionBounds(base::string16::size_type* start,
+                                        base::string16::size_type* end) const {
   if (![field_ currentEditor]) {
     *start = *end = 0;
     return;
@@ -359,11 +359,11 @@ void OmniboxViewMac::ApplyCaretVisibility() {
                             ofView:field_];
 }
 
-void OmniboxViewMac::SetText(const string16& display_text) {
+void OmniboxViewMac::SetText(const base::string16& display_text) {
   SetTextInternal(display_text);
 }
 
-void OmniboxViewMac::SetTextInternal(const string16& display_text) {
+void OmniboxViewMac::SetTextInternal(const base::string16& display_text) {
   NSString* ss = base::SysUTF16ToNSString(display_text);
   NSMutableAttributedString* as =
       [[[NSMutableAttributedString alloc] initWithString:ss] autorelease];
@@ -388,7 +388,7 @@ void OmniboxViewMac::SetTextInternal(const string16& display_text) {
   // text-field implementation.
 }
 
-void OmniboxViewMac::SetTextAndSelectedRange(const string16& display_text,
+void OmniboxViewMac::SetTextAndSelectedRange(const base::string16& display_text,
                                              const NSRange range) {
   SetText(display_text);
   SetSelectedRange(range);
@@ -414,7 +414,7 @@ void OmniboxViewMac::EmphasizeURLComponents() {
   }
 }
 
-void OmniboxViewMac::ApplyTextAttributes(const string16& display_text,
+void OmniboxViewMac::ApplyTextAttributes(const base::string16& display_text,
                                          NSMutableAttributedString* as) {
   NSUInteger as_length = [as length];
   NSRange as_entire_string = NSMakeRange(0, as_length);
@@ -484,9 +484,10 @@ void OmniboxViewMac::ApplyTextAttributes(const string16& display_text,
   }
 }
 
-void OmniboxViewMac::OnTemporaryTextMaybeChanged(const string16& display_text,
-                                                 bool save_original_selection,
-                                                 bool notify_text_changed) {
+void OmniboxViewMac::OnTemporaryTextMaybeChanged(
+    const base::string16& display_text,
+    bool save_original_selection,
+    bool notify_text_changed) {
   if (save_original_selection)
     saved_temporary_selection_ = GetSelectedRange();
 
@@ -497,7 +498,7 @@ void OmniboxViewMac::OnTemporaryTextMaybeChanged(const string16& display_text,
 }
 
 bool OmniboxViewMac::OnInlineAutocompleteTextMaybeChanged(
-    const string16& display_text,
+    const base::string16& display_text,
     size_t user_text_length) {
   // TODO(shess): Make sure that this actually works.  The round trip
   // to native form and back may mean that it's the same but not the
@@ -544,7 +545,7 @@ bool OmniboxViewMac::OnAfterPossibleChange() {
   DCHECK(IsFirstResponder());
 
   const NSRange new_selection(GetSelectedRange());
-  const string16 new_text(GetText());
+  const base::string16 new_text(GetText());
   const size_t length = new_text.length();
 
   const bool selection_differs =
@@ -600,7 +601,8 @@ gfx::NativeView OmniboxViewMac::GetRelativeWindowForPopup() const {
   return NULL;
 }
 
-void OmniboxViewMac::SetGrayTextAutocompletion(const string16& suggest_text) {
+void OmniboxViewMac::SetGrayTextAutocompletion(
+    const base::string16& suggest_text) {
   if (suggest_text == suggest_text_)
     return;
   suggest_text_ = suggest_text;
@@ -608,7 +610,7 @@ void OmniboxViewMac::SetGrayTextAutocompletion(const string16& suggest_text) {
                           textColor:SuggestTextColor()];
 }
 
-string16 OmniboxViewMac::GetGrayTextAutocompletion() const {
+base::string16 OmniboxViewMac::GetGrayTextAutocompletion() const {
   return suggest_text_;
 }
 
@@ -792,7 +794,7 @@ void OmniboxViewMac::CopyToPasteboard(NSPasteboard* pb) {
   DCHECK(CanCopy());
 
   const NSRange selection = GetSelectedRange();
-  string16 text = base::SysNSStringToUTF16(
+  base::string16 text = base::SysNSStringToUTF16(
       [[field_ stringValue] substringWithRange:selection]);
 
   // Copy the URL unless this is the search URL and it's being replaced by the
@@ -827,7 +829,7 @@ void OmniboxViewMac::OnPaste() {
   // This code currently expects |field_| to be focussed.
   DCHECK([field_ currentEditor]);
 
-  string16 text = GetClipboardText();
+  base::string16 text = GetClipboardText();
   if (text.empty()) {
     return;
   }
@@ -869,14 +871,14 @@ bool OmniboxViewMac::CanPasteAndGo() {
 }
 
 int OmniboxViewMac::GetPasteActionStringId() {
-  string16 text(GetClipboardText());
+  base::string16 text(GetClipboardText());
   DCHECK(model()->CanPasteAndGo(text));
   return model()->IsPasteAndSearch(text) ?
       IDS_PASTE_AND_SEARCH : IDS_PASTE_AND_GO;
 }
 
 void OmniboxViewMac::OnPasteAndGo() {
-  string16 text(GetClipboardText());
+  base::string16 text(GetClipboardText());
   if (model()->CanPasteAndGo(text))
     model()->PasteAndGo(text);
 }
diff --git a/chrome/browser/ui/cocoa/one_click_signin_dialog_controller.mm b/chrome/browser/ui/cocoa/one_click_signin_dialog_controller.mm
index 022e373..f0156f2 100644
--- a/chrome/browser/ui/cocoa/one_click_signin_dialog_controller.mm
+++ b/chrome/browser/ui/cocoa/one_click_signin_dialog_controller.mm
@@ -13,7 +13,7 @@
 OneClickSigninDialogController::OneClickSigninDialogController(
     content::WebContents* web_contents,
     const BrowserWindow::StartSyncCallback& sync_callback,
-    const string16& email) {
+    const base::string16& email) {
   base::Closure close_callback = base::Bind(
       &OneClickSigninDialogController::PerformClose, base::Unretained(this));
   view_controller_.reset([[OneClickSigninViewController alloc]
diff --git a/chrome/browser/ui/cocoa/one_click_signin_view_controller.h b/chrome/browser/ui/cocoa/one_click_signin_view_controller.h
index 751970a..df1f2d5 100644
--- a/chrome/browser/ui/cocoa/one_click_signin_view_controller.h
+++ b/chrome/browser/ui/cocoa/one_click_signin_view_controller.h
@@ -32,7 +32,7 @@ class WebContents;
   BOOL clickedLearnMore_;
 
   // The user's email address to be used for sync.
-  string16 email_;
+  base::string16 email_;
 
   // Alternate error message to be displayed.
   base::scoped_nsobject<NSString> errorMessage_;
@@ -57,7 +57,7 @@ class WebContents;
          syncCallback:(const BrowserWindow::StartSyncCallback&)syncCallback
         closeCallback:(const base::Closure&)callback
          isSyncDialog:(BOOL)isSyncDialog
-                email:(const string16&)email
+                email:(const base::string16&)email
          errorMessage:(NSString*)errorMessage;
 
 // Called before the view is closed.
diff --git a/chrome/browser/ui/cocoa/one_click_signin_view_controller.mm b/chrome/browser/ui/cocoa/one_click_signin_view_controller.mm
index be723e3..db6d681 100644
--- a/chrome/browser/ui/cocoa/one_click_signin_view_controller.mm
+++ b/chrome/browser/ui/cocoa/one_click_signin_view_controller.mm
@@ -44,7 +44,7 @@ void ShiftOriginY(NSView* view, CGFloat amount) {
          syncCallback:(const BrowserWindow::StartSyncCallback&)syncCallback
         closeCallback:(const base::Closure&)closeCallback
          isSyncDialog:(BOOL)isSyncDialog
-                email:(const string16&)email
+                email:(const base::string16&)email
          errorMessage:(NSString*)errorMessage {
   if ((self = [super initWithNibName:nibName
                               bundle:base::mac::FrameworkBundle()])) {
diff --git a/chrome/browser/ui/cocoa/profile_signin_confirmation_view_controller.mm b/chrome/browser/ui/cocoa/profile_signin_confirmation_view_controller.mm
index 4a84a92..e47e710 100644
--- a/chrome/browser/ui/cocoa/profile_signin_confirmation_view_controller.mm
+++ b/chrome/browser/ui/cocoa/profile_signin_confirmation_view_controller.mm
@@ -82,8 +82,8 @@ void RemoveUnderlining(NSTextView* textView, int offset, int length) {
 NSTextView* AddTextView(
     NSView* parent,
     id<NSTextViewDelegate> delegate,
-    const string16& message,
-    const string16& link,
+    const base::string16& message,
+    const base::string16& link,
     int offset,
     const ui::ResourceBundle::FontStyle& font_style) {
   base::scoped_nsobject<HyperlinkTextView> textView(
@@ -107,7 +107,7 @@ NSTextView* AddTextView(
 // Create a new NSTextField and add it to the specified parent.
 NSTextField* AddTextField(
     NSView* parent,
-    const string16& message,
+    const base::string16& message,
     const ui::ResourceBundle::FontStyle& font_style) {
   NSTextField* textField = constrained_window::CreateLabel();
   [textField setAttributedStringValue:
@@ -251,9 +251,10 @@ NSTextField* AddTextField(
 
   // Prompt text.
   size_t offset;
-  const string16 domain = ASCIIToUTF16(gaia::ExtractDomainName(username_));
-  const string16 username = ASCIIToUTF16(username_);
-  const string16 prompt_text =
+  const base::string16 domain =
+      ASCIIToUTF16(gaia::ExtractDomainName(username_));
+  const base::string16 username = ASCIIToUTF16(username_);
+  const base::string16 prompt_text =
       l10n_util::GetStringFUTF16(
           IDS_ENTERPRISE_SIGNIN_ALERT_NEW_STYLE,
           domain, &offset);
@@ -275,10 +276,10 @@ NSTextField* AddTextField(
 
   // Explanation text.
   std::vector<size_t> offsets;
-  const string16 learn_more_text =
+  const base::string16 learn_more_text =
       l10n_util::GetStringUTF16(
           IDS_ENTERPRISE_SIGNIN_PROFILE_LINK_LEARN_MORE);
-  const string16 explanation_text =
+  const base::string16 explanation_text =
       l10n_util::GetStringFUTF16(
           offerProfileCreation_ ?
           IDS_ENTERPRISE_SIGNIN_EXPLANATION_WITH_PROFILE_CREATION_NEW_STYLE :
@@ -288,7 +289,7 @@ NSTextField* AddTextField(
   // into the middle of the message text.  To do this we slice out
   // the "learn more" string from the message so that it can be
   // inserted again.
-  const string16 explanation_message_text =
+  const base::string16 explanation_message_text =
     explanation_text.substr(0, offsets[1]) +
     explanation_text.substr(offsets[1] + learn_more_text.size());
   explanationField_.reset(
diff --git a/chrome/browser/ui/cocoa/profile_signin_confirmation_view_controller_browsertest.mm b/chrome/browser/ui/cocoa/profile_signin_confirmation_view_controller_browsertest.mm
index 0d5a5c4..d477090 100644
--- a/chrome/browser/ui/cocoa/profile_signin_confirmation_view_controller_browsertest.mm
+++ b/chrome/browser/ui/cocoa/profile_signin_confirmation_view_controller_browsertest.mm
@@ -57,7 +57,7 @@ class ProfileSigninConfirmationViewControllerTest
   std::string username() {
     return "foo@bar.com";
   }
-  string16 learn_more() {
+  base::string16 learn_more() {
     return l10n_util::GetStringUTF16(
         IDS_ENTERPRISE_SIGNIN_PROFILE_LINK_LEARN_MORE);
   }
diff --git a/chrome/browser/ui/cocoa/screen_capture_notification_ui_cocoa.h b/chrome/browser/ui/cocoa/screen_capture_notification_ui_cocoa.h
index ca803a7..97126c8 100644
--- a/chrome/browser/ui/cocoa/screen_capture_notification_ui_cocoa.h
+++ b/chrome/browser/ui/cocoa/screen_capture_notification_ui_cocoa.h
@@ -22,14 +22,14 @@
 }
 
 - (id)initWithCallback:(const base::Closure&)stop_callback
-                  text:(const string16&)text;
+                  text:(const base::string16&)text;
 - (void)stopSharing:(id)sender;
 
 @end
 
 class ScreenCaptureNotificationUICocoa : public ScreenCaptureNotificationUI {
  public:
-  explicit ScreenCaptureNotificationUICocoa(const string16& text);
+  explicit ScreenCaptureNotificationUICocoa(const base::string16& text);
   virtual ~ScreenCaptureNotificationUICocoa();
 
   // ScreenCaptureNotificationUI interface.
@@ -38,7 +38,7 @@ class ScreenCaptureNotificationUICocoa : public ScreenCaptureNotificationUI {
  private:
   friend class ScreenCaptureNotificationUICocoaTest;
 
-  const string16 text_;
+  const base::string16 text_;
   base::scoped_nsobject<ScreenCaptureNotificationController> windowController_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenCaptureNotificationUICocoa);
diff --git a/chrome/browser/ui/cocoa/screen_capture_notification_ui_cocoa.mm b/chrome/browser/ui/cocoa/screen_capture_notification_ui_cocoa.mm
index 6f5cc4e..15b937a 100644
--- a/chrome/browser/ui/cocoa/screen_capture_notification_ui_cocoa.mm
+++ b/chrome/browser/ui/cocoa/screen_capture_notification_ui_cocoa.mm
@@ -34,7 +34,7 @@ const CGFloat kWindowCornerRadius = 2;
 
 @interface ScreenCaptureNotificationController()
 - (void)hide;
-- (void)populateWithText:(const string16&)text;
+- (void)populateWithText:(const base::string16&)text;
 @end
 
 @interface ScreenCaptureNotificationView : NSView
@@ -46,7 +46,7 @@ const CGFloat kWindowCornerRadius = 2;
 
 
 ScreenCaptureNotificationUICocoa::ScreenCaptureNotificationUICocoa(
-    const string16& text)
+    const base::string16& text)
     : text_(text) {
 }
 
@@ -64,14 +64,14 @@ void ScreenCaptureNotificationUICocoa::OnStarted(
 }
 
 scoped_ptr<ScreenCaptureNotificationUI> ScreenCaptureNotificationUI::Create(
-    const string16& text) {
+    const base::string16& text) {
   return scoped_ptr<ScreenCaptureNotificationUI>(
       new ScreenCaptureNotificationUICocoa(text));
 }
 
 @implementation ScreenCaptureNotificationController
 - (id)initWithCallback:(const base::Closure&)stop_callback
-                  text:(const string16&)text {
+                  text:(const base::string16&)text {
   base::scoped_nsobject<NSWindow> window(
       [[NSWindow alloc] initWithContentRect:ui::kWindowSizeDeterminedLater
                                   styleMask:NSBorderlessWindowMask
@@ -117,7 +117,7 @@ scoped_ptr<ScreenCaptureNotificationUI> ScreenCaptureNotificationUI::Create(
   [self close];
 }
 
-- (void)populateWithText:(const string16&)text {
+- (void)populateWithText:(const base::string16&)text {
   base::scoped_nsobject<ScreenCaptureNotificationView> content(
       [[ScreenCaptureNotificationView alloc]
           initWithFrame:ui::kWindowSizeDeterminedLater]);
@@ -151,7 +151,7 @@ scoped_ptr<ScreenCaptureNotificationUI> ScreenCaptureNotificationUI::Create(
   gfx::Font font(ui::ResourceBundle::GetSharedInstance()
                      .GetFont(ui::ResourceBundle::BaseFont)
                      .GetNativeFont());
-  string16 elidedText =
+  base::string16 elidedText =
       ElideText(text, font, maxLabelWidth, gfx::ELIDE_IN_MIDDLE);
   NSString* statusText = base::SysUTF16ToNSString(elidedText);
   base::scoped_nsobject<NSTextField> statusTextField(
diff --git a/chrome/browser/ui/cocoa/simple_message_box_mac.mm b/chrome/browser/ui/cocoa/simple_message_box_mac.mm
index cc956ee..883d527 100644
--- a/chrome/browser/ui/cocoa/simple_message_box_mac.mm
+++ b/chrome/browser/ui/cocoa/simple_message_box_mac.mm
@@ -14,8 +14,8 @@
 namespace chrome {
 
 MessageBoxResult ShowMessageBox(gfx::NativeWindow parent,
-                                const string16& title,
-                                const string16& message,
+                                const base::string16& title,
+                                const base::string16& message,
                                 MessageBoxType type) {
   if (type == MESSAGE_BOX_TYPE_OK_CANCEL)
     NOTIMPLEMENTED();
diff --git a/chrome/browser/ui/cocoa/speech_recognition_window_controller.h b/chrome/browser/ui/cocoa/speech_recognition_window_controller.h
index 9befe2c..24fa890 100644
--- a/chrome/browser/ui/cocoa/speech_recognition_window_controller.h
+++ b/chrome/browser/ui/cocoa/speech_recognition_window_controller.h
@@ -41,7 +41,7 @@
 
 // Updates the UI with data related to the given display mode.
 - (void)updateLayout:(SpeechRecognitionBubbleBase::DisplayMode)mode
-         messageText:(const string16&)messageText
+         messageText:(const base::string16&)messageText
            iconImage:(NSImage*)iconImage;
 
 // Makes the speech recognition bubble visible on screen.
diff --git a/chrome/browser/ui/cocoa/speech_recognition_window_controller.mm b/chrome/browser/ui/cocoa/speech_recognition_window_controller.mm
index 6a0969e..2048fb2 100644
--- a/chrome/browser/ui/cocoa/speech_recognition_window_controller.mm
+++ b/chrome/browser/ui/cocoa/speech_recognition_window_controller.mm
@@ -175,7 +175,7 @@ const int kInstructionLabelMaxWidth = 150;
 }
 
 - (void)updateLayout:(SpeechRecognitionBubbleBase::DisplayMode)mode
-         messageText:(const string16&)messageText
+         messageText:(const base::string16&)messageText
            iconImage:(NSImage*)iconImage {
   // The very first time this method is called, the child views would still be
   // uninitialized and null. So we invoke [self window] first and that sets up
diff --git a/chrome/browser/ui/cocoa/status_bubble_mac.h b/chrome/browser/ui/cocoa/status_bubble_mac.h
index d38c9e5..be7637f 100644
--- a/chrome/browser/ui/cocoa/status_bubble_mac.h
+++ b/chrome/browser/ui/cocoa/status_bubble_mac.h
@@ -35,7 +35,7 @@ class StatusBubbleMac : public StatusBubble {
   virtual ~StatusBubbleMac();
 
   // StatusBubble implementation.
-  virtual void SetStatus(const string16& status) OVERRIDE;
+  virtual void SetStatus(const base::string16& status) OVERRIDE;
   virtual void SetURL(const GURL& url, const std::string& languages) OVERRIDE;
   virtual void Hide() OVERRIDE;
   virtual void MouseMoved(const gfx::Point& location,
@@ -72,7 +72,7 @@ class StatusBubbleMac : public StatusBubble {
   void SetState(StatusBubbleState state);
 
   // Sets the bubble text for SetStatus and SetURL.
-  void SetText(const string16& text, bool is_url);
+  void SetText(const base::string16& text, bool is_url);
 
   // Construct the window/widget if it does not already exist. (Safe to call if
   // it does.)
diff --git a/chrome/browser/ui/cocoa/status_bubble_mac.mm b/chrome/browser/ui/cocoa/status_bubble_mac.mm
index d42cb29..2e5cdf8 100644
--- a/chrome/browser/ui/cocoa/status_bubble_mac.mm
+++ b/chrome/browser/ui/cocoa/status_bubble_mac.mm
@@ -124,7 +124,7 @@ StatusBubbleMac::~StatusBubbleMac() {
   window_ = nil;
 }
 
-void StatusBubbleMac::SetStatus(const string16& status) {
+void StatusBubbleMac::SetStatus(const base::string16& status) {
   SetText(status, false);
 }
 
@@ -153,8 +153,9 @@ void StatusBubbleMac::SetURL(const GURL& url, const std::string& languages) {
   gfx::FontList font_list_chr(
       gfx::Font(base::SysNSStringToUTF8([font fontName]), [font pointSize]));
 
-  string16 original_url_text = net::FormatUrl(url, languages);
-  string16 status = gfx::ElideUrl(url, font_list_chr, text_width, languages);
+  base::string16 original_url_text = net::FormatUrl(url, languages);
+  base::string16 status =
+      gfx::ElideUrl(url, font_list_chr, text_width, languages);
 
   SetText(status, true);
 
@@ -178,7 +179,7 @@ void StatusBubbleMac::SetURL(const GURL& url, const std::string& languages) {
   }
 }
 
-void StatusBubbleMac::SetText(const string16& text, bool is_url) {
+void StatusBubbleMac::SetText(const base::string16& text, bool is_url) {
   // The status bubble allows the status and URL strings to be set
   // independently.  Whichever was set non-empty most recently will be the
   // value displayed.  When both are empty, the status bubble hides.
@@ -623,7 +624,7 @@ void StatusBubbleMac::ExpandBubble() {
   NSFont* font = [[window_ contentView] font];
   gfx::FontList font_list_chr(
       gfx::Font(base::SysNSStringToUTF8([font fontName]), [font pointSize]));
-  string16 expanded_url = gfx::ElideUrl(
+  base::string16 expanded_url = gfx::ElideUrl(
       url_, font_list_chr, max_bubble_width, languages_);
 
   // Scale width from gfx::Font in view coordinates to window coordinates.
diff --git a/chrome/browser/ui/cocoa/status_icons/status_icon_mac.h b/chrome/browser/ui/cocoa/status_icons/status_icon_mac.h
index 6bd6570..c3f5cf0 100644
--- a/chrome/browser/ui/cocoa/status_icons/status_icon_mac.h
+++ b/chrome/browser/ui/cocoa/status_icons/status_icon_mac.h
@@ -26,10 +26,10 @@ class StatusIconMac : public StatusIcon {
   // Overridden from StatusIcon.
   virtual void SetImage(const gfx::ImageSkia& image) OVERRIDE;
   virtual void SetPressedImage(const gfx::ImageSkia& image) OVERRIDE;
-  virtual void SetToolTip(const string16& tool_tip) OVERRIDE;
+  virtual void SetToolTip(const base::string16& tool_tip) OVERRIDE;
   virtual void DisplayBalloon(const gfx::ImageSkia& icon,
-                              const string16& title,
-                              const string16& contents) OVERRIDE;
+                              const base::string16& title,
+                              const base::string16& contents) OVERRIDE;
 
   bool HasStatusIconMenu();
 
diff --git a/chrome/browser/ui/cocoa/status_icons/status_icon_mac.mm b/chrome/browser/ui/cocoa/status_icons/status_icon_mac.mm
index cc79fc6..32c1f81 100644
--- a/chrome/browser/ui/cocoa/status_icons/status_icon_mac.mm
+++ b/chrome/browser/ui/cocoa/status_icons/status_icon_mac.mm
@@ -79,7 +79,7 @@ void StatusIconMac::SetPressedImage(const gfx::ImageSkia& image) {
   }
 }
 
-void StatusIconMac::SetToolTip(const string16& tool_tip) {
+void StatusIconMac::SetToolTip(const base::string16& tool_tip) {
   // If we have a status icon menu, make the tool tip part of the menu instead
   // of a pop-up tool tip when hovering the mouse over the image.
   toolTip_.reset([base::SysUTF16ToNSString(tool_tip) retain]);
@@ -92,8 +92,8 @@ void StatusIconMac::SetToolTip(const string16& tool_tip) {
 }
 
 void StatusIconMac::DisplayBalloon(const gfx::ImageSkia& icon,
-                                   const string16& title,
-                                   const string16& contents) {
+                                   const base::string16& title,
+                                   const base::string16& contents) {
   notification_.DisplayBalloon(icon, title, contents);
 }
 
diff --git a/chrome/browser/ui/cocoa/status_icons/status_tray_mac.h b/chrome/browser/ui/cocoa/status_icons/status_tray_mac.h
index 7325d86..7496892 100644
--- a/chrome/browser/ui/cocoa/status_icons/status_tray_mac.h
+++ b/chrome/browser/ui/cocoa/status_icons/status_tray_mac.h
@@ -17,7 +17,7 @@ class StatusTrayMac : public StatusTray {
   virtual StatusIcon* CreatePlatformStatusIcon(
       StatusIconType type,
       const gfx::ImageSkia& image,
-      const string16& tool_tip) OVERRIDE;
+      const base::string16& tool_tip) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(StatusTrayMac);
diff --git a/chrome/browser/ui/cocoa/status_icons/status_tray_mac.mm b/chrome/browser/ui/cocoa/status_icons/status_tray_mac.mm
index 50dc797..bec5554 100644
--- a/chrome/browser/ui/cocoa/status_icons/status_tray_mac.mm
+++ b/chrome/browser/ui/cocoa/status_icons/status_tray_mac.mm
@@ -13,9 +13,10 @@ StatusTray* StatusTray::Create() {
 StatusTrayMac::StatusTrayMac() {
 }
 
-StatusIcon* StatusTrayMac::CreatePlatformStatusIcon(StatusIconType type,
-                                                    const gfx::ImageSkia& image,
-                                                    const string16& tool_tip) {
+StatusIcon* StatusTrayMac::CreatePlatformStatusIcon(
+    StatusIconType type,
+    const gfx::ImageSkia& image,
+    const base::string16& tool_tip) {
   StatusIcon* icon = new StatusIconMac();
   icon->SetImage(image);
   icon->SetToolTip(tool_tip);
diff --git a/chrome/browser/ui/cocoa/tab_contents/render_view_context_menu_mac.h b/chrome/browser/ui/cocoa/tab_contents/render_view_context_menu_mac.h
index c43503a..43afdd7 100644
--- a/chrome/browser/ui/cocoa/tab_contents/render_view_context_menu_mac.h
+++ b/chrome/browser/ui/cocoa/tab_contents/render_view_context_menu_mac.h
@@ -31,7 +31,7 @@ class RenderViewContextMenuMac : public RenderViewContextMenu {
   virtual void UpdateMenuItem(int command_id,
                               bool enabled,
                               bool hidden,
-                              const string16& title) OVERRIDE;
+                              const base::string16& title) OVERRIDE;
 
  protected:
   // RenderViewContextMenu implementation.
diff --git a/chrome/browser/ui/cocoa/tab_contents/render_view_context_menu_mac.mm b/chrome/browser/ui/cocoa/tab_contents/render_view_context_menu_mac.mm
index 4caf5ce..47c4516 100644
--- a/chrome/browser/ui/cocoa/tab_contents/render_view_context_menu_mac.mm
+++ b/chrome/browser/ui/cocoa/tab_contents/render_view_context_menu_mac.mm
@@ -265,7 +265,7 @@ void RenderViewContextMenuMac::StopSpeaking() {
 void RenderViewContextMenuMac::UpdateMenuItem(int command_id,
                                               bool enabled,
                                               bool hidden,
-                                              const string16& title) {
+                                              const base::string16& title) {
   NSMenuItem* item = GetMenuItemByID(&menu_model_, [menu_controller_ menu],
                                      command_id);
   if (!item)
diff --git a/chrome/browser/ui/cocoa/tab_contents/sad_tab_view.mm b/chrome/browser/ui/cocoa/tab_contents/sad_tab_view.mm
index 411ffff..769ea74 100644
--- a/chrome/browser/ui/cocoa/tab_contents/sad_tab_view.mm
+++ b/chrome/browser/ui/cocoa/tab_contents/sad_tab_view.mm
@@ -147,7 +147,7 @@ static const CGFloat kTabHorzMargin = 13;
   // Get the help text and link.
   size_t linkOffset = 0;
   NSString* helpMessage(base::SysUTF16ToNSString(l10n_util::GetStringFUTF16(
-      IDS_SAD_TAB_HELP_MESSAGE, string16(), &linkOffset)));
+      IDS_SAD_TAB_HELP_MESSAGE, base::string16(), &linkOffset)));
   NSString* helpLink = l10n_util::GetNSString(IDS_SAD_TAB_HELP_LINK);
   NSFont* font = [NSFont systemFontOfSize:[NSFont smallSystemFontSize]];
   [help_.get() setMessageAndLink:helpMessage
diff --git a/chrome/browser/ui/cocoa/tabpose_window.mm b/chrome/browser/ui/cocoa/tabpose_window.mm
index af5b80b..f4cc4fc 100644
--- a/chrome/browser/ui/cocoa/tabpose_window.mm
+++ b/chrome/browser/ui/cocoa/tabpose_window.mm
@@ -406,7 +406,7 @@ class Tile {
   NSRect title_rect() const { return NSIntegralRect(title_rect_); }
 
   // Returns an unelided title. The view logic is responsible for eliding.
-  const string16& title() const {
+  const base::string16& title() const {
     return contents_->GetTitle();
   }
 
diff --git a/chrome/browser/ui/cocoa/task_manager_mac_unittest.mm b/chrome/browser/ui/cocoa/task_manager_mac_unittest.mm
index 9dff6b1e..5bf1fe7 100644
--- a/chrome/browser/ui/cocoa/task_manager_mac_unittest.mm
+++ b/chrome/browser/ui/cocoa/task_manager_mac_unittest.mm
@@ -19,9 +19,12 @@ namespace {
 
 class TestResource : public task_manager::Resource {
  public:
-  TestResource(const string16& title, pid_t pid) : title_(title), pid_(pid) {}
-  virtual string16 GetTitle() const OVERRIDE { return title_; }
-  virtual string16 GetProfileName() const OVERRIDE { return string16(); }
+  TestResource(const base::string16& title, pid_t pid)
+      : title_(title), pid_(pid) {}
+  virtual base::string16 GetTitle() const OVERRIDE { return title_; }
+  virtual base::string16 GetProfileName() const OVERRIDE {
+    return base::string16();
+  }
   virtual gfx::ImageSkia GetIcon() const OVERRIDE { return gfx::ImageSkia(); }
   virtual base::ProcessHandle GetProcess() const OVERRIDE { return pid_; }
   virtual int GetUniqueChildProcessId() const OVERRIDE {
@@ -33,8 +36,8 @@ class TestResource : public task_manager::Resource {
   virtual bool SupportNetworkUsage() const OVERRIDE { return false; }
   virtual void SetSupportNetworkUsage() OVERRIDE { NOTREACHED(); }
   virtual void Refresh() OVERRIDE {}
-  string16 title_;
-  string16 profile_name_;
+  base::string16 title_;
+  base::string16 profile_name_;
   pid_t pid_;
 };
 
diff --git a/chrome/browser/ui/cocoa/ui_localizer.mm b/chrome/browser/ui/cocoa/ui_localizer.mm
index 273f3f4..139f93e 100644
--- a/chrome/browser/ui/cocoa/ui_localizer.mm
+++ b/chrome/browser/ui/cocoa/ui_localizer.mm
@@ -78,9 +78,9 @@ int ResourceMapCompare(const void* utf8Void,
     if (val) {
       // Do we need to build the string, or just fetch it?
       if (val->label_arg_id != 0) {
-        const string16 label_arg(l10n_util::GetStringUTF16(val->label_arg_id));
-        return l10n_util::GetNSStringFWithFixup(val->label_id,
-                                                label_arg);
+        const base::string16 label_arg(
+            l10n_util::GetStringUTF16(val->label_arg_id));
+        return l10n_util::GetNSStringFWithFixup(val->label_id, label_arg);
       }
 
       return l10n_util::GetNSStringWithFixup(val->label_id);
diff --git a/chrome/browser/ui/cocoa/validation_message_bubble_controller.h b/chrome/browser/ui/cocoa/validation_message_bubble_controller.h
index e010fab..7c8f78d 100644
--- a/chrome/browser/ui/cocoa/validation_message_bubble_controller.h
+++ b/chrome/browser/ui/cocoa/validation_message_bubble_controller.h
@@ -13,12 +13,12 @@
 
 - (id)init:(NSWindow*)parentWindow
 anchoredAt:(NSPoint)anchorPoint
-  mainText:(const string16&)mainText
-   subText:(const string16&)subText;
+  mainText:(const base::string16&)mainText
+   subText:(const base::string16&)subText;
 
 // This is exposed for testing.
-+ (NSView*)constructContentView:(const string16&)mainText
-                        subText:(const string16&)subText;
++ (NSView*)constructContentView:(const base::string16&)mainText
+                        subText:(const base::string16&)subText;
 
 @end
 
diff --git a/chrome/browser/ui/cocoa/web_dialog_window_controller.mm b/chrome/browser/ui/cocoa/web_dialog_window_controller.mm
index 4e7d2bf..d87ef92 100644
--- a/chrome/browser/ui/cocoa/web_dialog_window_controller.mm
+++ b/chrome/browser/ui/cocoa/web_dialog_window_controller.mm
@@ -46,7 +46,7 @@ public:
 
   // WebDialogDelegate declarations.
   virtual ui::ModalType GetDialogModalType() const OVERRIDE;
-  virtual string16 GetDialogTitle() const OVERRIDE;
+  virtual base::string16 GetDialogTitle() const OVERRIDE;
   virtual GURL GetDialogContentURL() const OVERRIDE;
   virtual void GetWebUIMessageHandlers(
       std::vector<WebUIMessageHandler*>* handlers) const OVERRIDE;
@@ -151,7 +151,7 @@ ui::ModalType WebDialogWindowDelegateBridge::GetDialogModalType() const {
 }
 
 string16 WebDialogWindowDelegateBridge::GetDialogTitle() const {
-  return delegate_ ? delegate_->GetDialogTitle() : string16();
+  return delegate_ ? delegate_->GetDialogTitle() : base::string16();
 }
 
 GURL WebDialogWindowDelegateBridge::GetDialogContentURL() const {
diff --git a/chrome/browser/ui/cocoa/web_dialog_window_controller_unittest.mm b/chrome/browser/ui/cocoa/web_dialog_window_controller_unittest.mm
index c3bb0d6..be10630 100644
--- a/chrome/browser/ui/cocoa/web_dialog_window_controller_unittest.mm
+++ b/chrome/browser/ui/cocoa/web_dialog_window_controller_unittest.mm
@@ -33,7 +33,7 @@ namespace {
 class MockDelegate : public WebDialogDelegate {
 public:
   MOCK_CONST_METHOD0(GetDialogModalType, ui::ModalType());
-  MOCK_CONST_METHOD0(GetDialogTitle, string16());
+  MOCK_CONST_METHOD0(GetDialogTitle, base::string16());
   MOCK_CONST_METHOD0(GetDialogContentURL, GURL());
   MOCK_CONST_METHOD1(GetWebUIMessageHandlers,
                      void(std::vector<WebUIMessageHandler*>*));
@@ -56,7 +56,7 @@ class WebDialogWindowControllerTest : public BrowserWithTestWindowTest {
   }
 
  protected:
-  string16 title_;
+  base::string16 title_;
   gfx::Size size_;
   GURL gurl_;
 
diff --git a/chrome/browser/ui/cocoa/website_settings_bubble_controller.h b/chrome/browser/ui/cocoa/website_settings_bubble_controller.h
index 5f671e7..dcf3849 100644
--- a/chrome/browser/ui/cocoa/website_settings_bubble_controller.h
+++ b/chrome/browser/ui/cocoa/website_settings_bubble_controller.h
@@ -119,7 +119,7 @@ class WebsiteSettingsUIBridge : public WebsiteSettingsUI {
   virtual void SetPermissionInfo(
       const PermissionInfoList& permission_info_list) OVERRIDE;
   virtual void SetIdentityInfo(const IdentityInfo& identity_info) OVERRIDE;
-  virtual void SetFirstVisit(const string16& first_visit) OVERRIDE;
+  virtual void SetFirstVisit(const base::string16& first_visit) OVERRIDE;
   virtual void SetSelectedTab(TabId tab_id) OVERRIDE;
 
  private:
diff --git a/chrome/browser/ui/cocoa/website_settings_bubble_controller.mm b/chrome/browser/ui/cocoa/website_settings_bubble_controller.mm
index d131376..d39bb7e 100644
--- a/chrome/browser/ui/cocoa/website_settings_bubble_controller.mm
+++ b/chrome/browser/ui/cocoa/website_settings_bubble_controller.mm
@@ -359,7 +359,7 @@ NSColor* IdentityVerifiedTextColor() {
   [imageView setImage:rb.GetNativeImageNamed(IDR_PRODUCT_LOGO_26).ToNSImage()];
 
   controlOrigin.x += NSWidth([imageView frame]) + kInternalPageImageSpacing;
-  string16 text = l10n_util::GetStringUTF16(IDS_PAGE_INFO_INTERNAL_PAGE);
+  base::string16 text = l10n_util::GetStringUTF16(IDS_PAGE_INFO_INTERNAL_PAGE);
   NSTextField* textField = [self addText:text
                                 withSize:[NSFont smallSystemFontSize]
                                     bold:NO
@@ -768,7 +768,7 @@ NSColor* IdentityVerifiedTextColor() {
 
 // Create a new text field and add it to the given array of subviews.
 // The array will retain a reference to the object.
-- (NSTextField*)addText:(const string16&)text
+- (NSTextField*)addText:(const base::string16&)text
                withSize:(CGFloat)fontSize
                    bold:(BOOL)bold
                  toView:(NSView*)view
@@ -893,7 +893,7 @@ NSColor* IdentityVerifiedTextColor() {
 
   // Set the button title.
   base::scoped_nsobject<NSMenuItem> titleItem([[NSMenuItem alloc] init]);
-  string16 buttonTitle = WebsiteSettingsUI::PermissionActionToUIString(
+  base::string16 buttonTitle = WebsiteSettingsUI::PermissionActionToUIString(
       permissionInfo.setting,
       permissionInfo.default_setting,
       permissionInfo.source);
@@ -905,7 +905,7 @@ NSColor* IdentityVerifiedTextColor() {
   // Determine the largest possible size for this button.
   CGFloat maxTitleWidth = 0;
   for (NSInteger i = 0; i < [button numberOfItems]; ++i) {
-    string16 title = WebsiteSettingsUI::PermissionActionToUIString(
+    base::string16 title = WebsiteSettingsUI::PermissionActionToUIString(
         static_cast<ContentSetting>([[button itemAtIndex:i] tag]),
         permissionInfo.default_setting,
         content_settings::SETTING_SOURCE_USER);
@@ -962,7 +962,7 @@ NSColor* IdentityVerifiedTextColor() {
   [imageView setImage:image];
   point.x += kPermissionImageSize + kPermissionImageSpacing;
 
-  string16 labelText =
+  base::string16 labelText =
       WebsiteSettingsUI::PermissionTypeToUIString(permissionInfo.type) +
       ASCIIToUTF16(":");
 
@@ -1027,7 +1027,7 @@ NSColor* IdentityVerifiedTextColor() {
   [imageView setImage:image];
   point.x += kPermissionImageSize + kPermissionImageSpacing;
 
-  string16 labelText = l10n_util::GetStringFUTF16(
+  base::string16 labelText = l10n_util::GetStringFUTF16(
       IDS_WEBSITE_SETTINGS_SITE_DATA_STATS_LINE,
       UTF8ToUTF16(cookieInfo.cookie_source),
       base::IntToString16(cookieInfo.allowed),
@@ -1094,7 +1094,7 @@ NSColor* IdentityVerifiedTextColor() {
   [cookiesView_ setSubviews:[NSArray array]];
   NSPoint controlOrigin = NSMakePoint(kFramePadding, 0);
 
-  string16 sectionTitle = l10n_util::GetStringUTF16(
+  base::string16 sectionTitle = l10n_util::GetStringUTF16(
       IDS_WEBSITE_SETTINGS_TITLE_SITE_DATA);
   NSTextField* header = [self addText:sectionTitle
                              withSize:[NSFont smallSystemFontSize]
@@ -1124,7 +1124,7 @@ NSColor* IdentityVerifiedTextColor() {
   [permissionsView_ setSubviews:[NSArray array]];
   NSPoint controlOrigin = NSMakePoint(kFramePadding, 0);
 
-  string16 sectionTitle = l10n_util::GetStringUTF16(
+  base::string16 sectionTitle = l10n_util::GetStringUTF16(
       IDS_WEBSITE_SETTINGS_TITLE_SITE_PERMISSIONS);
   NSTextField* header = [self addText:sectionTitle
                              withSize:[NSFont smallSystemFontSize]
@@ -1150,7 +1150,7 @@ NSColor* IdentityVerifiedTextColor() {
   [self performLayout];
 }
 
-- (void)setFirstVisit:(const string16&)firstVisit {
+- (void)setFirstVisit:(const base::string16&)firstVisit {
   [firstVisitIcon_ setImage:
       WebsiteSettingsUI::GetFirstVisitIcon(firstVisit).ToNSImage()];
   [firstVisitDescriptionField_ setStringValue:
@@ -1228,7 +1228,7 @@ void WebsiteSettingsUIBridge::SetPermissionInfo(
   [bubble_controller_ setPermissionInfo:permission_info_list];
 }
 
-void WebsiteSettingsUIBridge::SetFirstVisit(const string16& first_visit) {
+void WebsiteSettingsUIBridge::SetFirstVisit(const base::string16& first_visit) {
   [bubble_controller_ setFirstVisit:first_visit];
 }
 
diff --git a/chrome/browser/ui/cocoa/wrench_menu/wrench_menu_controller.mm b/chrome/browser/ui/cocoa/wrench_menu/wrench_menu_controller.mm
index 23eb0b8..4ac09ad 100644
--- a/chrome/browser/ui/cocoa/wrench_menu/wrench_menu_controller.mm
+++ b/chrome/browser/ui/cocoa/wrench_menu/wrench_menu_controller.mm
@@ -79,7 +79,7 @@ class ZoomLevelObserver {
   void OnZoomLevelChanged(const HostZoomMap::ZoomLevelChange& change) {
     WrenchMenuModel* wrenchMenuModel = [controller_ wrenchMenuModel];
     wrenchMenuModel->UpdateZoomControls();
-    const string16 level =
+    const base::string16 level =
         wrenchMenuModel->GetLabelForCommandId(IDC_ZOOM_PERCENT_DISPLAY);
     [[controller_ zoomDisplay] setTitle:SysUTF16ToNSString(level)];
   }
@@ -170,7 +170,7 @@ class ZoomLevelObserver {
     } else {
       // Not a section header. Add a tooltip with the title and the URL.
       std::string url;
-      string16 title;
+      base::string16 title;
       if ([self recentTabsMenuModel]->GetURLAndTitleForItemAtIndex(
               [item tag], &url, &title)) {
         [menuItem setToolTip:
diff --git a/chrome/browser/ui/cocoa/wrench_menu/wrench_menu_controller_unittest.mm b/chrome/browser/ui/cocoa/wrench_menu/wrench_menu_controller_unittest.mm
index 15547fc..29472bc 100644
--- a/chrome/browser/ui/cocoa/wrench_menu/wrench_menu_controller_unittest.mm
+++ b/chrome/browser/ui/cocoa/wrench_menu/wrench_menu_controller_unittest.mm
@@ -134,9 +134,9 @@ TEST_F(WrenchMenuControllerTest, RecentTabsElideTitle) {
   RecentTabsBuilderTestHelper recent_tabs_builder;
   recent_tabs_builder.AddSession();
   recent_tabs_builder.AddWindow(0);
-  string16 tab1_short_title = ASCIIToUTF16("Short");
+  base::string16 tab1_short_title = ASCIIToUTF16("Short");
   recent_tabs_builder.AddTabWithInfo(0, 0, base::Time::Now(), tab1_short_title);
-  string16 tab2_long_title = ASCIIToUTF16("Very very very very very very "
+  base::string16 tab2_long_title = ASCIIToUTF16("Very very very very very very "
                                           "very very very very very very long");
   recent_tabs_builder.AddTabWithInfo(0, 0,
       base::Time::Now() - base::TimeDelta::FromMinutes(10), tab2_long_title);
diff --git a/chrome/browser/ui/collected_cookies_infobar_delegate.h b/chrome/browser/ui/collected_cookies_infobar_delegate.h
index 2fb053a..7bed4fb 100644
--- a/chrome/browser/ui/collected_cookies_infobar_delegate.h
+++ b/chrome/browser/ui/collected_cookies_infobar_delegate.h
@@ -27,9 +27,9 @@ class CollectedCookiesInfoBarDelegate : public ConfirmInfoBarDelegate {
   // ConfirmInfoBarDelegate:
   virtual int GetIconID() const OVERRIDE;
   virtual Type GetInfoBarType() const OVERRIDE;
-  virtual string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
   virtual int GetButtons() const OVERRIDE;
-  virtual string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
+  virtual base::string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
   virtual bool Accept() OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(CollectedCookiesInfoBarDelegate);
diff --git a/chrome/browser/ui/confirm_bubble_model.h b/chrome/browser/ui/confirm_bubble_model.h
index c6c95c7..e5a8b59 100644
--- a/chrome/browser/ui/confirm_bubble_model.h
+++ b/chrome/browser/ui/confirm_bubble_model.h
@@ -29,8 +29,8 @@ class ConfirmBubbleModel {
 
   // Returns the title string and the message string to be displayed for this
   // bubble menu. These must not be empty strings.
-  virtual string16 GetTitle() const = 0;
-  virtual string16 GetMessageText() const = 0;
+  virtual base::string16 GetTitle() const = 0;
+  virtual base::string16 GetMessageText() const = 0;
 
   // Returns an icon for the bubble. This image should be owned by the
   // ResourceBundle and callers should not take ownership of it. Must not return
@@ -45,7 +45,7 @@ class ConfirmBubbleModel {
 
   // Return the label for the specified button. The default implementation
   // returns "OK" for the OK button and "Cancel" for the Cancel button.
-  virtual string16 GetButtonLabel(BubbleButton button) const;
+  virtual base::string16 GetButtonLabel(BubbleButton button) const;
 
   // Called when the OK button is pressed.
   virtual void Accept();
@@ -55,7 +55,7 @@ class ConfirmBubbleModel {
 
   // Returns the text of the link to be displayed, if any. Otherwise returns
   // and empty string.
-  virtual string16 GetLinkText() const;
+  virtual base::string16 GetLinkText() const;
 
   // Called when the Link is clicked.
   virtual void LinkClicked();
diff --git a/chrome/browser/ui/external_protocol_dialog_delegate.cc b/chrome/browser/ui/external_protocol_dialog_delegate.cc
index e0129c2..2badc31 100644
--- a/chrome/browser/ui/external_protocol_dialog_delegate.cc
+++ b/chrome/browser/ui/external_protocol_dialog_delegate.cc
@@ -28,15 +28,15 @@ string16 ExternalProtocolDialogDelegate::GetMessageText() const {
   // TODO(calamity): Look up the command in ExternalProtocolHandler and pass it
   // into the constructor. Will require simultaneous change of
   // ExternalProtocolHandler::RunExternalProtocolDialog across all platforms.
-  string16 command =
+  base::string16 command =
     UTF8ToUTF16(ShellIntegration::GetApplicationForProtocol(url()));
-  string16 elided_url_without_scheme;
-  string16 elided_command;
+  base::string16 elided_url_without_scheme;
+  base::string16 elided_command;
   gfx::ElideString(ASCIIToUTF16(url().possibly_invalid_spec()),
                   kMaxUrlWithoutSchemeSize, &elided_url_without_scheme);
   gfx::ElideString(command, kMaxCommandSize, &elided_command);
 
-  string16 message_text = l10n_util::GetStringFUTF16(
+  base::string16 message_text = l10n_util::GetStringFUTF16(
       IDS_EXTERNAL_PROTOCOL_INFORMATION,
       ASCIIToUTF16(url().scheme() + ":"),
       elided_url_without_scheme) + ASCIIToUTF16("\n\n");
diff --git a/chrome/browser/ui/external_protocol_dialog_delegate.h b/chrome/browser/ui/external_protocol_dialog_delegate.h
index 1fccfb9..85de91e 100644
--- a/chrome/browser/ui/external_protocol_dialog_delegate.h
+++ b/chrome/browser/ui/external_protocol_dialog_delegate.h
@@ -21,9 +21,9 @@ class ExternalProtocolDialogDelegate : public ProtocolDialogDelegate {
   virtual void DoAccept(const GURL& url, bool dont_block) const OVERRIDE;
   virtual void DoCancel(const GURL& url, bool dont_block) const OVERRIDE;
 
-  virtual string16 GetMessageText() const OVERRIDE;
-  virtual string16 GetCheckboxText() const OVERRIDE;
-  virtual string16 GetTitleText() const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetCheckboxText() const OVERRIDE;
+  virtual base::string16 GetTitleText() const OVERRIDE;
 };
 
 #endif  // CHROME_BROWSER_UI_EXTERNAL_PROTOCOL_DIALOG_DELEGATE_H_
diff --git a/chrome/browser/ui/libgtk2ui/app_indicator_icon.cc b/chrome/browser/ui/libgtk2ui/app_indicator_icon.cc
index dc2fffd..b2378fa 100644
--- a/chrome/browser/ui/libgtk2ui/app_indicator_icon.cc
+++ b/chrome/browser/ui/libgtk2ui/app_indicator_icon.cc
@@ -165,7 +165,7 @@ namespace libgtk2ui {
 
 AppIndicatorIcon::AppIndicatorIcon(std::string id,
                                    const gfx::ImageSkia& image,
-                                   const string16& tool_tip)
+                                   const base::string16& tool_tip)
     : id_(id),
       icon_(NULL),
       gtk_menu_(NULL),
@@ -222,7 +222,7 @@ void AppIndicatorIcon::SetPressedImage(const gfx::ImageSkia& image) {
   // pressed status icons.
 }
 
-void AppIndicatorIcon::SetToolTip(const string16& tool_tip) {
+void AppIndicatorIcon::SetToolTip(const base::string16& tool_tip) {
   DCHECK(!tool_tip_.empty());
   tool_tip_ = UTF16ToUTF8(tool_tip);
 
diff --git a/chrome/browser/ui/libgtk2ui/app_indicator_icon.h b/chrome/browser/ui/libgtk2ui/app_indicator_icon.h
index 8b0f0d9..99da811 100644
--- a/chrome/browser/ui/libgtk2ui/app_indicator_icon.h
+++ b/chrome/browser/ui/libgtk2ui/app_indicator_icon.h
@@ -29,7 +29,7 @@ class AppIndicatorIcon : public views::StatusIconLinux {
   // icons.
   AppIndicatorIcon(std::string id,
                    const gfx::ImageSkia& image,
-                   const string16& tool_tip);
+                   const base::string16& tool_tip);
   virtual ~AppIndicatorIcon();
 
   // Indicates whether libappindicator so could be opened.
@@ -38,7 +38,7 @@ class AppIndicatorIcon : public views::StatusIconLinux {
   // Overridden from views::StatusIconLinux:
   virtual void SetImage(const gfx::ImageSkia& image) OVERRIDE;
   virtual void SetPressedImage(const gfx::ImageSkia& image) OVERRIDE;
-  virtual void SetToolTip(const string16& tool_tip) OVERRIDE;
+  virtual void SetToolTip(const base::string16& tool_tip) OVERRIDE;
   virtual void UpdatePlatformContextMenu(ui::MenuModel* menu) OVERRIDE;
   virtual void RefreshPlatformContextMenu() OVERRIDE;
 
diff --git a/chrome/browser/ui/libgtk2ui/gtk2_ui.cc b/chrome/browser/ui/libgtk2ui/gtk2_ui.cc
index ec8a11a..8fa7cd3 100644
--- a/chrome/browser/ui/libgtk2ui/gtk2_ui.cc
+++ b/chrome/browser/ui/libgtk2ui/gtk2_ui.cc
@@ -475,7 +475,7 @@ bool Gtk2UI::IsStatusIconSupported() const {
 
 scoped_ptr<views::StatusIconLinux> Gtk2UI::CreateLinuxStatusIcon(
     const gfx::ImageSkia& image,
-    const string16& tool_tip) const {
+    const base::string16& tool_tip) const {
   if (AppIndicatorIcon::CouldOpen()) {
     ++indicators_count;
     return scoped_ptr<views::StatusIconLinux>(new AppIndicatorIcon(
diff --git a/chrome/browser/ui/libgtk2ui/gtk2_ui.h b/chrome/browser/ui/libgtk2ui/gtk2_ui.h
index eaebae7..4c22f01 100644
--- a/chrome/browser/ui/libgtk2ui/gtk2_ui.h
+++ b/chrome/browser/ui/libgtk2ui/gtk2_ui.h
@@ -72,7 +72,7 @@ class Gtk2UI : public views::LinuxUI {
   virtual bool IsStatusIconSupported() const OVERRIDE;
   virtual scoped_ptr<views::StatusIconLinux> CreateLinuxStatusIcon(
       const gfx::ImageSkia& image,
-      const string16& tool_tip) const OVERRIDE;
+      const base::string16& tool_tip) const OVERRIDE;
   virtual gfx::Image GetIconForContentType(
       const std::string& content_type, int size) const OVERRIDE;
   virtual void AddWindowButtonOrderObserver(
diff --git a/chrome/browser/ui/libgtk2ui/select_file_dialog_impl.h b/chrome/browser/ui/libgtk2ui/select_file_dialog_impl.h
index 89db17c..5429fdb 100644
--- a/chrome/browser/ui/libgtk2ui/select_file_dialog_impl.h
+++ b/chrome/browser/ui/libgtk2ui/select_file_dialog_impl.h
@@ -51,7 +51,7 @@ class SelectFileDialogImpl : public ui::SelectFileDialog {
   // |params| is user data we pass back via the Listener interface.
   virtual void SelectFileImpl(
       Type type,
-      const string16& title,
+      const base::string16& title,
       const base::FilePath& default_path,
       const FileTypeInfo* file_types,
       int file_type_index,
diff --git a/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_gtk2.cc b/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_gtk2.cc
index 5778d6c..eda5b26 100644
--- a/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_gtk2.cc
+++ b/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_gtk2.cc
@@ -79,7 +79,7 @@ class SelectFileDialogImplGTK : public SelectFileDialogImpl,
   // |params| is user data we pass back via the Listener interface.
   virtual void SelectFileImpl(
       Type type,
-      const string16& title,
+      const base::string16& title,
       const base::FilePath& default_path,
       const FileTypeInfo* file_types,
       int file_type_index,
@@ -215,7 +215,7 @@ void SelectFileDialogImplGTK::OnWindowDestroying(aura::Window* window) {
 // We ignore |default_extension|.
 void SelectFileDialogImplGTK::SelectFileImpl(
     Type type,
-    const string16& title,
+    const base::string16& title,
     const base::FilePath& default_path,
     const FileTypeInfo* file_types,
     int file_type_index,
diff --git a/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_kde.cc b/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_kde.cc
index a0178a7..db284ba 100644
--- a/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_kde.cc
+++ b/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_kde.cc
@@ -56,7 +56,7 @@ class SelectFileDialogImplKDE : public SelectFileDialogImpl {
   // |params| is user data we pass back via the Listener interface.
   virtual void SelectFileImpl(
       Type type,
-      const string16& title,
+      const base::string16& title,
       const base::FilePath& default_path,
       const FileTypeInfo* file_types,
       int file_type_index,
@@ -187,7 +187,7 @@ SelectFileDialogImplKDE::~SelectFileDialogImplKDE() {
 // We ignore |default_extension|.
 void SelectFileDialogImplKDE::SelectFileImpl(
     Type type,
-    const string16& title,
+    const base::string16& title,
     const base::FilePath& default_path,
     const FileTypeInfo* file_types,
     int file_type_index,
diff --git a/chrome/browser/ui/pdf/open_pdf_in_reader_prompt_delegate.h b/chrome/browser/ui/pdf/open_pdf_in_reader_prompt_delegate.h
index 980b70d..c39d66a 100644
--- a/chrome/browser/ui/pdf/open_pdf_in_reader_prompt_delegate.h
+++ b/chrome/browser/ui/pdf/open_pdf_in_reader_prompt_delegate.h
@@ -15,11 +15,11 @@ class OpenPDFInReaderPromptDelegate {
  public:
   virtual ~OpenPDFInReaderPromptDelegate() {}
 
-  virtual string16 GetMessageText() const = 0;
+  virtual base::string16 GetMessageText() const = 0;
 
-  virtual string16 GetAcceptButtonText() const = 0;
+  virtual base::string16 GetAcceptButtonText() const = 0;
 
-  virtual string16 GetCancelButtonText() const = 0;
+  virtual base::string16 GetCancelButtonText() const = 0;
 
   virtual bool ShouldExpire(
       const content::LoadCommittedDetails& details) const = 0;
diff --git a/chrome/browser/ui/pdf/pdf_browsertest.cc b/chrome/browser/ui/pdf/pdf_browsertest.cc
index 784741b..105feac 100644
--- a/chrome/browser/ui/pdf/pdf_browsertest.cc
+++ b/chrome/browser/ui/pdf/pdf_browsertest.cc
@@ -114,7 +114,7 @@ class PDFBrowserTest : public InProcessBrowserTest,
     // renderer code will think the second message is to go to next result, but
     // there are none so the plugin will assert.
 
-    string16 query = UTF8ToUTF16(
+    base::string16 query = UTF8ToUTF16(
         std::string("xyzxyz" + base::IntToString(next_dummy_search_value_++)));
     ASSERT_EQ(0, ui_test_utils::FindInPage(
         browser()->tab_strip_model()->GetActiveWebContents(),
diff --git a/chrome/browser/ui/pdf/pdf_tab_helper.cc b/chrome/browser/ui/pdf/pdf_tab_helper.cc
index 4785105..66336fc 100644
--- a/chrome/browser/ui/pdf/pdf_tab_helper.cc
+++ b/chrome/browser/ui/pdf/pdf_tab_helper.cc
@@ -96,7 +96,7 @@ void PDFTabHelper::OnUpdateContentRestrictions(int content_restrictions) {
 void PDFTabHelper::OnModalPromptForPasswordClosed(
     IPC::Message* reply_message,
     bool success,
-    const string16& actual_value) {
+    const base::string16& actual_value) {
   ChromeViewHostMsg_PDFModalPromptForPassword::WriteReplyParams(
       reply_message, UTF16ToUTF8(actual_value));
   Send(reply_message);
@@ -104,7 +104,7 @@ void PDFTabHelper::OnModalPromptForPasswordClosed(
 
 void PDFTabHelper::OnModalPromptForPassword(const std::string& prompt,
                                             IPC::Message* reply_message) {
-  base::Callback<void(bool, const string16&)> callback =
+  base::Callback<void(bool, const base::string16&)> callback =
       base::Bind(&PDFTabHelper::OnModalPromptForPasswordClosed,
                  base::Unretained(this), reply_message);
 #if !defined(TOOLKIT_GTK)
diff --git a/chrome/browser/ui/pdf/pdf_tab_helper.h b/chrome/browser/ui/pdf/pdf_tab_helper.h
index 6b7809b..04ae744 100644
--- a/chrome/browser/ui/pdf/pdf_tab_helper.h
+++ b/chrome/browser/ui/pdf/pdf_tab_helper.h
@@ -45,7 +45,7 @@ class PDFTabHelper : public content::WebContentsObserver,
   void UpdateLocationBar();
   void OnModalPromptForPasswordClosed(IPC::Message* reply_message,
                                       bool success,
-                                      const string16& actual_value);
+                                      const base::string16& actual_value);
 
   // Message handlers.
   void OnHasUnsupportedFeature();
diff --git a/chrome/browser/ui/pdf/pdf_unsupported_feature.cc b/chrome/browser/ui/pdf/pdf_unsupported_feature.cc
index f31fc5b..924d882 100644
--- a/chrome/browser/ui/pdf/pdf_unsupported_feature.cc
+++ b/chrome/browser/ui/pdf/pdf_unsupported_feature.cc
@@ -70,9 +70,9 @@ class PDFEnableAdobeReaderPromptDelegate
   virtual ~PDFEnableAdobeReaderPromptDelegate();
 
   // OpenPDFInReaderPromptDelegate
-  virtual string16 GetMessageText() const OVERRIDE;
-  virtual string16 GetAcceptButtonText() const OVERRIDE;
-  virtual string16 GetCancelButtonText() const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetAcceptButtonText() const OVERRIDE;
+  virtual base::string16 GetCancelButtonText() const OVERRIDE;
   virtual bool ShouldExpire(
       const content::LoadCommittedDetails& details) const OVERRIDE;
   virtual void Accept() OVERRIDE;
@@ -251,9 +251,9 @@ class PDFUnsupportedFeaturePromptDelegate
   virtual ~PDFUnsupportedFeaturePromptDelegate();
 
   // OpenPDFInReaderPromptDelegate:
-  virtual string16 GetMessageText() const OVERRIDE;
-  virtual string16 GetAcceptButtonText() const OVERRIDE;
-  virtual string16 GetCancelButtonText() const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetAcceptButtonText() const OVERRIDE;
+  virtual base::string16 GetCancelButtonText() const OVERRIDE;
   virtual bool ShouldExpire(
       const content::LoadCommittedDetails& details) const OVERRIDE;
   virtual void Accept() OVERRIDE;
diff --git a/chrome/browser/ui/search_engines/edit_search_engine_controller.cc b/chrome/browser/ui/search_engines/edit_search_engine_controller.cc
index 096ed4c..287d5e2 100644
--- a/chrome/browser/ui/search_engines/edit_search_engine_controller.cc
+++ b/chrome/browser/ui/search_engines/edit_search_engine_controller.cc
@@ -27,7 +27,7 @@ EditSearchEngineController::EditSearchEngineController(
 }
 
 bool EditSearchEngineController::IsTitleValid(
-    const string16& title_input) const {
+    const base::string16& title_input) const {
   return !CollapseWhitespace(title_input, true).empty();
 }
 
@@ -62,8 +62,8 @@ bool EditSearchEngineController::IsURLValid(
 }
 
 bool EditSearchEngineController::IsKeywordValid(
-    const string16& keyword_input) const {
-  string16 keyword_input_trimmed(CollapseWhitespace(keyword_input, true));
+    const base::string16& keyword_input) const {
+  base::string16 keyword_input_trimmed(CollapseWhitespace(keyword_input, true));
   if (keyword_input_trimmed.empty())
     return false;  // Do not allow empty keyword.
   const TemplateURL* turl_with_keyword =
@@ -73,8 +73,8 @@ bool EditSearchEngineController::IsKeywordValid(
 }
 
 void EditSearchEngineController::AcceptAddOrEdit(
-    const string16& title_input,
-    const string16& keyword_input,
+    const base::string16& title_input,
+    const base::string16& keyword_input,
     const std::string& url_input) {
   DCHECK(!keyword_input.empty());
   std::string url_string = GetFixedUpURL(url_input);
diff --git a/chrome/browser/ui/search_engines/edit_search_engine_controller.h b/chrome/browser/ui/search_engines/edit_search_engine_controller.h
index 9835528..278b344 100644
--- a/chrome/browser/ui/search_engines/edit_search_engine_controller.h
+++ b/chrome/browser/ui/search_engines/edit_search_engine_controller.h
@@ -21,8 +21,8 @@ class EditSearchEngineControllerDelegate {
   // indicates a new TemplateURL should be created rather than modifying an
   // existing TemplateURL.
   virtual void OnEditedKeyword(TemplateURL* template_url,
-                               const string16& title,
-                               const string16& keyword,
+                               const base::string16& title,
+                               const base::string16& keyword,
                                const std::string& url) = 0;
 
  protected:
@@ -41,7 +41,7 @@ class EditSearchEngineController {
   ~EditSearchEngineController() {}
 
   // Returns true if the value of |title_input| is a valid search engine name.
-  bool IsTitleValid(const string16& title_input) const;
+  bool IsTitleValid(const base::string16& title_input) const;
 
   // Returns true if the value of |url_input| represents a valid search engine
   // URL. The URL is valid if it contains no search terms and is a valid
@@ -52,11 +52,11 @@ class EditSearchEngineController {
   // Returns true if the value of |keyword_input| represents a valid keyword.
   // The keyword is valid if it is non-empty and does not conflict with an
   // existing entry. NOTE: this is just the keyword, not the title and url.
-  bool IsKeywordValid(const string16& keyword_input) const;
+  bool IsKeywordValid(const base::string16& keyword_input) const;
 
   // Completes the add or edit of a search engine.
-  void AcceptAddOrEdit(const string16& title_input,
-                       const string16& keyword_input,
+  void AcceptAddOrEdit(const base::string16& title_input,
+                       const base::string16& keyword_input,
                        const std::string& url_input);
 
   // Deletes an unused TemplateURL, if its add was cancelled and it's not
diff --git a/chrome/browser/ui/search_engines/keyword_editor_controller.cc b/chrome/browser/ui/search_engines/keyword_editor_controller.cc
index 57630ee..a5cfdf4 100644
--- a/chrome/browser/ui/search_engines/keyword_editor_controller.cc
+++ b/chrome/browser/ui/search_engines/keyword_editor_controller.cc
@@ -32,8 +32,8 @@ void KeywordEditorController::RegisterPrefs(PrefRegistrySimple* registry) {
   registry->RegisterDictionaryPref(prefs::kKeywordEditorWindowPlacement);
 }
 
-int KeywordEditorController::AddTemplateURL(const string16& title,
-                                            const string16& keyword,
+int KeywordEditorController::AddTemplateURL(const base::string16& title,
+                                            const base::string16& keyword,
                                             const std::string& url) {
   DCHECK(!url.empty());
 
@@ -46,8 +46,8 @@ int KeywordEditorController::AddTemplateURL(const string16& title,
 }
 
 void KeywordEditorController::ModifyTemplateURL(TemplateURL* template_url,
-                                                const string16& title,
-                                                const string16& keyword,
+                                                const base::string16& title,
+                                                const base::string16& keyword,
                                                 const std::string& url) {
   DCHECK(!url.empty());
   const int index = table_model_->IndexOfTemplateURL(template_url);
diff --git a/chrome/browser/ui/search_engines/keyword_editor_controller.h b/chrome/browser/ui/search_engines/keyword_editor_controller.h
index a6877ae..656f8f8 100644
--- a/chrome/browser/ui/search_engines/keyword_editor_controller.h
+++ b/chrome/browser/ui/search_engines/keyword_editor_controller.h
@@ -27,15 +27,15 @@ class KeywordEditorController {
   // Invoked when the user succesfully fills out the add keyword dialog.
   // Propagates the change to the TemplateURLService and updates the table
   // model.  Returns the index of the added URL.
-  int AddTemplateURL(const string16& title,
-                     const string16& keyword,
+  int AddTemplateURL(const base::string16& title,
+                     const base::string16& keyword,
                      const std::string& url);
 
   // Invoked when the user modifies a TemplateURL. Updates the
   // TemplateURLService and table model appropriately.
   void ModifyTemplateURL(TemplateURL* template_url,
-                         const string16& title,
-                         const string16& keyword,
+                         const base::string16& title,
+                         const base::string16& keyword,
                          const std::string& url);
 
   // Return true if the given |url| can be edited.
diff --git a/chrome/browser/ui/search_engines/keyword_editor_controller_unittest.cc b/chrome/browser/ui/search_engines/keyword_editor_controller_unittest.cc
index d967269..d4d293c 100644
--- a/chrome/browser/ui/search_engines/keyword_editor_controller_unittest.cc
+++ b/chrome/browser/ui/search_engines/keyword_editor_controller_unittest.cc
@@ -19,10 +19,10 @@
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/base/models/table_model_observer.h"
 
-static const string16 kA(ASCIIToUTF16("a"));
-static const string16 kA1(ASCIIToUTF16("a1"));
-static const string16 kB(ASCIIToUTF16("b"));
-static const string16 kB1(ASCIIToUTF16("b1"));
+static const base::string16 kA(ASCIIToUTF16("a"));
+static const base::string16 kA1(ASCIIToUTF16("a1"));
+static const base::string16 kB(ASCIIToUTF16("b"));
+static const base::string16 kB1(ASCIIToUTF16("b1"));
 
 // Base class for keyword editor tests. Creates a profile containing an
 // empty TemplateURLService.
diff --git a/chrome/browser/ui/search_engines/search_engine_tab_helper.cc b/chrome/browser/ui/search_engines/search_engine_tab_helper.cc
index dada154..736dcda 100644
--- a/chrome/browser/ui/search_engines/search_engine_tab_helper.cc
+++ b/chrome/browser/ui/search_engines/search_engine_tab_helper.cc
@@ -37,7 +37,7 @@ string16 GenerateKeywordFromNavigationEntry(const NavigationEntry* entry) {
   // Don't autogenerate keywords for pages that are the result of form
   // submissions.
   if (IsFormSubmit(entry))
-    return string16();
+    return base::string16();
 
   // We want to use the user typed URL if available since that represents what
   // the user typed to get here, and fall back on the regular URL if not.
@@ -45,7 +45,7 @@ string16 GenerateKeywordFromNavigationEntry(const NavigationEntry* entry) {
   if (!url.is_valid()) {
     url = entry->GetURL();
     if (!url.is_valid())
-      return string16();
+      return base::string16();
   }
 
   // Don't autogenerate keywords for referrers that are anything other than HTTP
@@ -55,7 +55,7 @@ string16 GenerateKeywordFromNavigationEntry(const NavigationEntry* entry) {
   // elements and update AutocompletePopup to look for keywords using the path.
   // See http://b/issue?id=863583.
   if (!url.SchemeIs(content::kHttpScheme) || (url.path().length() > 1))
-    return string16();
+    return base::string16();
 
   return TemplateURLService::GenerateKeyword(url);
 }
@@ -122,7 +122,7 @@ void SearchEngineTabHelper::OnPageHasOSDD(
 
   // Autogenerate a keyword for the autodetected case; in the other cases we'll
   // generate a keyword later after fetching the OSDD.
-  string16 keyword;
+  base::string16 keyword;
   if (provider_type == TemplateURLFetcher::AUTODETECTED_PROVIDER) {
     keyword = GenerateKeywordFromNavigationEntry(entry);
     if (keyword.empty())
@@ -155,7 +155,7 @@ void SearchEngineTabHelper::GenerateKeywordIfNecessary(
   if (last_index <= 0)
     return;
 
-  string16 keyword(GenerateKeywordFromNavigationEntry(
+  base::string16 keyword(GenerateKeywordFromNavigationEntry(
       controller.GetEntryAtIndex(last_index - 1)));
   if (keyword.empty())
     return;
diff --git a/chrome/browser/ui/search_engines/template_url_table_model.cc b/chrome/browser/ui/search_engines/template_url_table_model.cc
index dffbc50..c0d45a3 100644
--- a/chrome/browser/ui/search_engines/template_url_table_model.cc
+++ b/chrome/browser/ui/search_engines/template_url_table_model.cc
@@ -187,7 +187,7 @@ string16 TemplateURLTableModel::GetText(int row, int col_id) {
   DCHECK(row >= 0 && row < RowCount());
   const TemplateURL* url = entries_[row]->template_url();
   if (col_id == IDS_SEARCH_ENGINES_EDITOR_DESCRIPTION_COLUMN) {
-    string16 url_short_name = url->short_name();
+    base::string16 url_short_name = url->short_name();
     // TODO(xji): Consider adding a special case if the short name is a URL,
     // since those should always be displayed LTR. Please refer to
     // http://crbug.com/6726 for more information.
@@ -261,8 +261,8 @@ void TemplateURLTableModel::Remove(int index) {
 }
 
 void TemplateURLTableModel::Add(int index,
-                                const string16& short_name,
-                                const string16& keyword,
+                                const base::string16& short_name,
+                                const base::string16& keyword,
                                 const std::string& url) {
   DCHECK(index >= 0 && index <= RowCount());
   DCHECK(!url.empty());
@@ -279,8 +279,8 @@ void TemplateURLTableModel::Add(int index,
 }
 
 void TemplateURLTableModel::ModifyTemplateURL(int index,
-                                              const string16& title,
-                                              const string16& keyword,
+                                              const base::string16& title,
+                                              const base::string16& keyword,
                                               const std::string& url) {
   DCHECK(index >= 0 && index <= RowCount());
   DCHECK(!url.empty());
diff --git a/chrome/browser/ui/search_engines/template_url_table_model.h b/chrome/browser/ui/search_engines/template_url_table_model.h
index 864b48c..07a075a9 100644
--- a/chrome/browser/ui/search_engines/template_url_table_model.h
+++ b/chrome/browser/ui/search_engines/template_url_table_model.h
@@ -47,7 +47,7 @@ class TemplateURLTableModel : public ui::TableModel,
 
   // ui::TableModel overrides.
   virtual int RowCount() OVERRIDE;
-  virtual string16 GetText(int row, int column) OVERRIDE;
+  virtual base::string16 GetText(int row, int column) OVERRIDE;
   virtual gfx::ImageSkia GetIcon(int row) OVERRIDE;
   virtual void SetObserver(ui::TableModelObserver* observer) OVERRIDE;
   virtual bool HasGroups() OVERRIDE;
@@ -59,14 +59,14 @@ class TemplateURLTableModel : public ui::TableModel,
 
   // Adds a new entry at the specified index.
   void Add(int index,
-           const string16& short_name,
-           const string16& keyword,
+           const base::string16& short_name,
+           const base::string16& keyword,
            const std::string& url);
 
   // Update the entry at the specified index.
   void ModifyTemplateURL(int index,
-                         const string16& title,
-                         const string16& keyword,
+                         const base::string16& title,
+                         const base::string16& keyword,
                          const std::string& url);
 
   // Reloads the icon at the specified index.
diff --git a/chrome/browser/ui/simple_message_box.h b/chrome/browser/ui/simple_message_box.h
index 5ce59e6..c289379 100644
--- a/chrome/browser/ui/simple_message_box.h
+++ b/chrome/browser/ui/simple_message_box.h
@@ -31,8 +31,8 @@ enum MessageBoxType {
 // We have a variety of other surfaces such as wrench menu notifications and
 // infobars; consult the UI leads for a recommendation.
 MessageBoxResult ShowMessageBox(gfx::NativeWindow parent,
-                                const string16& title,
-                                const string16& message,
+                                const base::string16& title,
+                                const base::string16& message,
                                 MessageBoxType type);
 
 // Shows a dialog box with the given |title| and |message|, and with two buttons
@@ -43,10 +43,10 @@ MessageBoxResult ShowMessageBox(gfx::NativeWindow parent,
 // We have a variety of other surfaces such as wrench menu notifications and
 // infobars; consult the UI leads for a recommendation.
 MessageBoxResult ShowMessageBoxWithButtonText(gfx::NativeWindow parent,
-                                              const string16& title,
-                                              const string16& message,
-                                              const string16& yes_text,
-                                              const string16& no_text);
+                                              const base::string16& title,
+                                              const base::string16& message,
+                                              const base::string16& yes_text,
+                                              const base::string16& no_text);
 
 }  // namespace chrome
 
diff --git a/chrome/browser/ui/startup/autolaunch_prompt_win.cc b/chrome/browser/ui/startup/autolaunch_prompt_win.cc
index c10eab7..da35243 100644
--- a/chrome/browser/ui/startup/autolaunch_prompt_win.cc
+++ b/chrome/browser/ui/startup/autolaunch_prompt_win.cc
@@ -49,8 +49,8 @@ class AutolaunchInfoBarDelegate : public ConfirmInfoBarDelegate {
 
   // ConfirmInfoBarDelegate:
   virtual int GetIconID() const OVERRIDE;
-  virtual string16 GetMessageText() const OVERRIDE;
-  virtual string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
   virtual bool Accept() OVERRIDE;
   virtual bool Cancel() OVERRIDE;
   virtual bool ShouldExpireInternal(
diff --git a/chrome/browser/ui/startup/default_browser_prompt.cc b/chrome/browser/ui/startup/default_browser_prompt.cc
index e24fe2c..99ea6e2 100644
--- a/chrome/browser/ui/startup/default_browser_prompt.cc
+++ b/chrome/browser/ui/startup/default_browser_prompt.cc
@@ -74,8 +74,8 @@ class DefaultBrowserInfoBarDelegate : public ConfirmInfoBarDelegate {
 
   // ConfirmInfoBarDelegate:
   virtual int GetIconID() const OVERRIDE;
-  virtual string16 GetMessageText() const OVERRIDE;
-  virtual string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
   virtual bool NeedElevation(InfoBarButton button) const OVERRIDE;
   virtual bool Accept() OVERRIDE;
   virtual bool Cancel() OVERRIDE;
diff --git a/chrome/browser/ui/startup/google_api_keys_infobar_delegate.h b/chrome/browser/ui/startup/google_api_keys_infobar_delegate.h
index c949761..23bfb1e 100644
--- a/chrome/browser/ui/startup/google_api_keys_infobar_delegate.h
+++ b/chrome/browser/ui/startup/google_api_keys_infobar_delegate.h
@@ -23,9 +23,9 @@ class GoogleApiKeysInfoBarDelegate : public ConfirmInfoBarDelegate {
   GoogleApiKeysInfoBarDelegate();
   virtual ~GoogleApiKeysInfoBarDelegate();
 
-  virtual string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
   virtual int GetButtons() const OVERRIDE;
-  virtual string16 GetLinkText() const OVERRIDE;
+  virtual base::string16 GetLinkText() const OVERRIDE;
   virtual bool LinkClicked(WindowOpenDisposition disposition) OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(GoogleApiKeysInfoBarDelegate);
diff --git a/chrome/browser/ui/startup/obsolete_os_infobar_delegate.h b/chrome/browser/ui/startup/obsolete_os_infobar_delegate.h
index 3e0eec5..727716a 100644
--- a/chrome/browser/ui/startup/obsolete_os_infobar_delegate.h
+++ b/chrome/browser/ui/startup/obsolete_os_infobar_delegate.h
@@ -24,9 +24,9 @@ class ObsoleteOSInfoBarDelegate : public ConfirmInfoBarDelegate {
   ObsoleteOSInfoBarDelegate();
   virtual ~ObsoleteOSInfoBarDelegate();
 
-  virtual string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
   virtual int GetButtons() const OVERRIDE;
-  virtual string16 GetLinkText() const OVERRIDE;
+  virtual base::string16 GetLinkText() const OVERRIDE;
   virtual bool LinkClicked(WindowOpenDisposition disposition) OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(ObsoleteOSInfoBarDelegate);
diff --git a/chrome/browser/ui/startup/session_crashed_infobar_delegate.h b/chrome/browser/ui/startup/session_crashed_infobar_delegate.h
index 260a320..1437709 100644
--- a/chrome/browser/ui/startup/session_crashed_infobar_delegate.h
+++ b/chrome/browser/ui/startup/session_crashed_infobar_delegate.h
@@ -23,9 +23,9 @@ class SessionCrashedInfoBarDelegate : public ConfirmInfoBarDelegate {
 
   // ConfirmInfoBarDelegate:
   virtual int GetIconID() const OVERRIDE;
-  virtual string16 GetMessageText() const OVERRIDE;
+  virtual base::string16 GetMessageText() const OVERRIDE;
   virtual int GetButtons() const OVERRIDE;
-  virtual string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
+  virtual base::string16 GetButtonLabel(InfoBarButton button) const OVERRIDE;
   virtual bool Accept() OVERRIDE;
 
   bool accepted_;
diff --git a/chrome/browser/ui/startup/startup_browser_creator.cc b/chrome/browser/ui/startup/startup_browser_creator.cc
index edb7d02..42bd266 100644
--- a/chrome/browser/ui/startup/startup_browser_creator.cc
+++ b/chrome/browser/ui/startup/startup_browser_creator.cc
@@ -783,7 +783,7 @@ void StartupBrowserCreator::ProcessCommandLineAlreadyRunning(
   if (!profile) {
     profile_manager->CreateProfileAsync(profile_path,
         base::Bind(&StartupBrowserCreator::ProcessCommandLineOnProfileCreated,
-                   command_line, cur_dir), string16(), string16(),
+                   command_line, cur_dir), base::string16(), base::string16(),
                    std::string());
     return;
   }
diff --git a/chrome/browser/ui/startup/startup_browser_creator_impl.cc b/chrome/browser/ui/startup/startup_browser_creator_impl.cc
index b6b9833..bf21acc 100644
--- a/chrome/browser/ui/startup/startup_browser_creator_impl.cc
+++ b/chrome/browser/ui/startup/startup_browser_creator_impl.cc
@@ -140,9 +140,9 @@ LaunchMode GetLaunchShortcutKind() {
   if (si.dwFlags & 0x800) {
     if (!si.lpTitle)
       return LM_SHORTCUT_NONAME;
-    string16 shortcut(si.lpTitle);
+    base::string16 shortcut(si.lpTitle);
     // The windows quick launch path is not localized.
-    if (shortcut.find(L"\\Quick Launch\\") != string16::npos) {
+    if (shortcut.find(L"\\Quick Launch\\") != base::string16::npos) {
       if (base::win::GetVersion() >= base::win::VERSION_WIN7)
         return LM_SHORTCUT_TASKBAR;
       else
diff --git a/chrome/browser/ui/startup/startup_browser_creator_win.cc b/chrome/browser/ui/startup/startup_browser_creator_win.cc
index a53e900..f946e77 100644
--- a/chrome/browser/ui/startup/startup_browser_creator_win.cc
+++ b/chrome/browser/ui/startup/startup_browser_creator_win.cc
@@ -16,7 +16,7 @@
 namespace chrome {
 
 GURL GetURLToOpen(Profile* profile) {
-  string16 params;
+  base::string16 params;
   base::win::MetroLaunchType launch_type =
       base::win::GetMetroLaunchParams(&params);
   if ((launch_type == base::win::METRO_PROTOCOL) ||
diff --git a/chrome/browser/ui/tab_contents/core_tab_helper.cc b/chrome/browser/ui/tab_contents/core_tab_helper.cc
index e0d59bf..e8c165e 100644
--- a/chrome/browser/ui/tab_contents/core_tab_helper.cc
+++ b/chrome/browser/ui/tab_contents/core_tab_helper.cc
@@ -51,7 +51,7 @@ string16 CoreTabHelper::GetDefaultTitle() {
 string16 CoreTabHelper::GetStatusText() const {
   if (!web_contents()->IsLoading() ||
       web_contents()->GetLoadState().state == net::LOAD_STATE_IDLE) {
-    return string16();
+    return base::string16();
   }
 
   switch (web_contents()->GetLoadState().state) {
@@ -104,7 +104,7 @@ string16 CoreTabHelper::GetStatusText() const {
       break;
   }
 
-  return string16();
+  return base::string16();
 }
 
 void CoreTabHelper::OnCloseStarted() {
diff --git a/chrome/browser/ui/tab_contents/core_tab_helper.h b/chrome/browser/ui/tab_contents/core_tab_helper.h
index 767c1fe..a5ca820 100644
--- a/chrome/browser/ui/tab_contents/core_tab_helper.h
+++ b/chrome/browser/ui/tab_contents/core_tab_helper.h
@@ -18,10 +18,10 @@ class CoreTabHelper : public content::WebContentsObserver,
   virtual ~CoreTabHelper();
 
   // Initial title assigned to NavigationEntries from Navigate.
-  static string16 GetDefaultTitle();
+  static base::string16 GetDefaultTitle();
 
   // Returns a human-readable description the tab's loading state.
-  string16 GetStatusText() const;
+  base::string16 GetStatusText() const;
 
   // Notification that tab closing has started.  This can be called multiple
   // times, subsequent calls are ignored.
diff --git a/chrome/browser/ui/tab_modal_confirm_dialog_browsertest.cc b/chrome/browser/ui/tab_modal_confirm_dialog_browsertest.cc
index 148b816..5e0c2ba 100644
--- a/chrome/browser/ui/tab_modal_confirm_dialog_browsertest.cc
+++ b/chrome/browser/ui/tab_modal_confirm_dialog_browsertest.cc
@@ -27,11 +27,11 @@ MockTabModalConfirmDialogDelegate::~MockTabModalConfirmDialogDelegate() {
 }
 
 string16 MockTabModalConfirmDialogDelegate::GetTitle() {
-  return string16();
+  return base::string16();
 }
 
 string16 MockTabModalConfirmDialogDelegate::GetMessage() {
-  return string16();
+  return base::string16();
 }
 
 void MockTabModalConfirmDialogDelegate::OnAccepted() {
diff --git a/chrome/browser/ui/tab_modal_confirm_dialog_browsertest.h b/chrome/browser/ui/tab_modal_confirm_dialog_browsertest.h
index a45e3d1..93d72b4 100644
--- a/chrome/browser/ui/tab_modal_confirm_dialog_browsertest.h
+++ b/chrome/browser/ui/tab_modal_confirm_dialog_browsertest.h
@@ -26,8 +26,8 @@ class MockTabModalConfirmDialogDelegate : public TabModalConfirmDialogDelegate {
                                     Delegate* delegate);
   virtual ~MockTabModalConfirmDialogDelegate();
 
-  virtual string16 GetTitle() OVERRIDE;
-  virtual string16 GetMessage() OVERRIDE;
+  virtual base::string16 GetTitle() OVERRIDE;
+  virtual base::string16 GetMessage() OVERRIDE;
 
   virtual void OnAccepted() OVERRIDE;
   virtual void OnCanceled() OVERRIDE;
diff --git a/chrome/browser/ui/toolbar/back_forward_menu_model.cc b/chrome/browser/ui/toolbar/back_forward_menu_model.cc
index db4efe2..f3f702e 100644
--- a/chrome/browser/ui/toolbar/back_forward_menu_model.cc
+++ b/chrome/browser/ui/toolbar/back_forward_menu_model.cc
@@ -97,20 +97,20 @@ string16 BackForwardMenuModel::GetLabelAt(int index) const {
 
   // Return an empty string for a separator.
   if (IsSeparator(index))
-    return string16();
+    return base::string16();
 
   // Return the entry title, escaping any '&' characters and eliding it if it's
   // super long.
   NavigationEntry* entry = GetNavigationEntry(index);
   Profile* profile =
       Profile::FromBrowserContext(GetWebContents()->GetBrowserContext());
-  string16 menu_text(entry->GetTitleForDisplay(
+  base::string16 menu_text(entry->GetTitleForDisplay(
       profile->GetPrefs()->GetString(prefs::kAcceptLanguages)));
   menu_text =
       gfx::ElideText(menu_text, gfx::Font(), kMaxWidth, gfx::ELIDE_AT_END);
 
 #if !defined(OS_MACOSX)
-  for (size_t i = menu_text.find('&'); i != string16::npos;
+  for (size_t i = menu_text.find('&'); i != base::string16::npos;
        i = menu_text.find('&', i + 2)) {
     menu_text.insert(i, 1, '&');
   }
diff --git a/chrome/browser/ui/toolbar/back_forward_menu_model.h b/chrome/browser/ui/toolbar/back_forward_menu_model.h
index be08f00..41cecd1 100644
--- a/chrome/browser/ui/toolbar/back_forward_menu_model.h
+++ b/chrome/browser/ui/toolbar/back_forward_menu_model.h
@@ -60,7 +60,7 @@ class BackForwardMenuModel : public ui::MenuModel {
   virtual ItemType GetTypeAt(int index) const OVERRIDE;
   virtual ui::MenuSeparatorType GetSeparatorTypeAt(int index) const OVERRIDE;
   virtual int GetCommandIdAt(int index) const OVERRIDE;
-  virtual string16 GetLabelAt(int index) const OVERRIDE;
+  virtual base::string16 GetLabelAt(int index) const OVERRIDE;
   virtual bool IsItemDynamicAt(int index) const OVERRIDE;
   virtual bool GetAcceleratorAt(int index,
                                 ui::Accelerator* accelerator) const OVERRIDE;
@@ -173,7 +173,7 @@ class BackForwardMenuModel : public ui::MenuModel {
   bool ItemHasIcon(int index) const;
 
   // Allow the unit test to use the "Show Full History" label.
-  string16 GetShowFullHistoryLabel() const;
+  base::string16 GetShowFullHistoryLabel() const;
 
   // Looks up a NavigationEntry by menu id.
   content::NavigationEntry* GetNavigationEntry(int index) const;
diff --git a/chrome/browser/ui/toolbar/encoding_menu_controller.cc b/chrome/browser/ui/toolbar/encoding_menu_controller.cc
index ddaedb7..789abbb 100644
--- a/chrome/browser/ui/toolbar/encoding_menu_controller.cc
+++ b/chrome/browser/ui/toolbar/encoding_menu_controller.cc
@@ -105,7 +105,7 @@ void EncodingMenuController::GetEncodingMenuItems(Profile* profile,
     EncodingMenuItemList* menu_items) {
 
   DCHECK(menu_items);
-  EncodingMenuItem separator(0, string16());
+  EncodingMenuItem separator(0, base::string16());
 
   menu_items->clear();
   menu_items->push_back(
@@ -130,7 +130,7 @@ void EncodingMenuController::GetEncodingMenuItems(Profile* profile,
   std::vector<CharacterEncoding::EncodingInfo>::const_iterator it;
   for (it = encodings->begin(); it != encodings->end(); ++it) {
     if (it->encoding_id) {
-      string16 encoding = it->encoding_display_name;
+      base::string16 encoding = it->encoding_display_name;
       base::i18n::AdjustStringForLocaleDirection(&encoding);
       menu_items->push_back(EncodingMenuItem(it->encoding_id, encoding));
     } else {
diff --git a/chrome/browser/ui/toolbar/encoding_menu_controller.h b/chrome/browser/ui/toolbar/encoding_menu_controller.h
index 9be4ed4..ea4563a 100644
--- a/chrome/browser/ui/toolbar/encoding_menu_controller.h
+++ b/chrome/browser/ui/toolbar/encoding_menu_controller.h
@@ -22,7 +22,7 @@ class EncodingMenuController {
   FRIEND_TEST_ALL_PREFIXES(EncodingMenuControllerTest, IsItemChecked);
 
  public:
-  typedef std::pair<int, string16> EncodingMenuItem;
+  typedef std::pair<int, base::string16> EncodingMenuItem;
   typedef std::vector<EncodingMenuItem> EncodingMenuItemList;
 
  public:
diff --git a/chrome/browser/ui/toolbar/recent_tabs_builder_test_helper.cc b/chrome/browser/ui/toolbar/recent_tabs_builder_test_helper.cc
index 1fa9d5c..9c40eab 100644
--- a/chrome/browser/ui/toolbar/recent_tabs_builder_test_helper.cc
+++ b/chrome/browser/ui/toolbar/recent_tabs_builder_test_helper.cc
@@ -20,7 +20,7 @@ const char kBaseTabUrl[] = "http://foo/?";
 const char kTabTitleFormat[] = "session=%d;window=%d;tab=%d";
 
 struct TitleTimestampPair {
-  string16 title;
+  base::string16 title;
   base::Time timestamp;
 };
 
@@ -61,7 +61,7 @@ struct RecentTabsBuilderTestHelper::TabInfo {
   TabInfo() : id(0) {}
   SessionID::id_type id;
   base::Time timestamp;
-  string16 title;
+  base::string16 title;
 };
 struct RecentTabsBuilderTestHelper::WindowInfo {
   WindowInfo() : id(0) {}
@@ -131,13 +131,13 @@ SessionID::id_type RecentTabsBuilderTestHelper::GetWindowID(int session_index,
 void RecentTabsBuilderTestHelper::AddTab(int session_index, int window_index) {
   base::Time timestamp =
       start_time_ + base::TimeDelta::FromMinutes(base::RandUint64());
-  AddTabWithInfo(session_index, window_index, timestamp, string16());
+  AddTabWithInfo(session_index, window_index, timestamp, base::string16());
 }
 
 void RecentTabsBuilderTestHelper::AddTabWithInfo(int session_index,
                                                  int window_index,
                                                  base::Time timestamp,
-                                                 const string16& title) {
+                                                 const base::string16& title) {
   TabInfo tab_info;
   tab_info.id = CreateUniqueID();
   tab_info.timestamp = timestamp;
@@ -166,7 +166,7 @@ base::Time RecentTabsBuilderTestHelper::GetTabTimestamp(int session_index,
 string16 RecentTabsBuilderTestHelper::GetTabTitle(int session_index,
                                                   int window_index,
                                                   int tab_index) {
-  string16 title =
+  base::string16 title =
       sessions_[session_index].windows[window_index].tabs[tab_index].title;
   if (title.empty()) {
     title = UTF8ToUTF16(ToTabTitle(
diff --git a/chrome/browser/ui/toolbar/recent_tabs_builder_test_helper.h b/chrome/browser/ui/toolbar/recent_tabs_builder_test_helper.h
index ac7492b..4d5727c 100644
--- a/chrome/browser/ui/toolbar/recent_tabs_builder_test_helper.h
+++ b/chrome/browser/ui/toolbar/recent_tabs_builder_test_helper.h
@@ -37,7 +37,7 @@ class RecentTabsBuilderTestHelper {
   void AddTabWithInfo(int session_index,
                       int window_index,
                       base::Time timestamp,
-                      const string16& title);
+                      const base::string16& title);
   int GetTabCount(int session_index, int window_index);
   SessionID::id_type GetTabID(int session_index,
                               int window_index,
@@ -45,7 +45,7 @@ class RecentTabsBuilderTestHelper {
   base::Time GetTabTimestamp(int session_index,
                              int window_index,
                              int tab_index);
-  string16 GetTabTitle(int session_index,
+  base::string16 GetTabTitle(int session_index,
                        int window_index,
                        int tab_index);
 
diff --git a/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.cc b/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.cc
index 702275f..88ab1a4 100644
--- a/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.cc
+++ b/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.cc
@@ -142,7 +142,7 @@ struct RecentTabsSubMenuModel::TabNavigationItem {
 
   TabNavigationItem(const std::string& session_tag,
                     const SessionID::id_type& tab_id,
-                    const string16& title,
+                    const base::string16& title,
                     const GURL& url)
       : session_tag(session_tag),
         tab_id(tab_id),
@@ -157,7 +157,7 @@ struct RecentTabsSubMenuModel::TabNavigationItem {
   // Empty for local tabs, non-empty for other devices' tabs.
   std::string session_tag;
   SessionID::id_type tab_id;  // -1 for invalid, >= 0 otherwise.
-  string16 title;
+  base::string16 title;
   GURL url;
 };
 
@@ -333,9 +333,10 @@ int RecentTabsSubMenuModel::GetMaxWidthForItemAtIndex(int item_index) const {
   return 320;
 }
 
-bool RecentTabsSubMenuModel::GetURLAndTitleForItemAtIndex(int index,
-                                                          std::string* url,
-                                                          string16* title) {
+bool RecentTabsSubMenuModel::GetURLAndTitleForItemAtIndex(
+    int index,
+    std::string* url,
+    base::string16* title) {
   int command_id = GetCommandIdAt(index);
   if (IsTabModelCommandId(command_id)) {
     TabNavigationItems* tab_items = NULL;
@@ -498,7 +499,7 @@ void RecentTabsSubMenuModel::BuildTabsFromOtherDevices() {
 }
 
 void RecentTabsSubMenuModel::BuildLocalTabItem(int session_id,
-                                               const string16& title,
+                                               const base::string16& title,
                                                const GURL& url,
                                                int curr_model_index) {
   TabNavigationItem item(std::string(), session_id, title, url);
diff --git a/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.h b/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.h
index ad175ad..b4c102c 100644
--- a/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.h
+++ b/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.h
@@ -66,7 +66,7 @@ class RecentTabsSubMenuModel : public ui::SimpleMenuModel,
   int GetMaxWidthForItemAtIndex(int item_index) const;
   bool GetURLAndTitleForItemAtIndex(int index,
                                     std::string* url,
-                                    string16* title);
+                                    base::string16* title);
 
  private:
   struct TabNavigationItem;
@@ -86,7 +86,7 @@ class RecentTabsSubMenuModel : public ui::SimpleMenuModel,
   // Build a recently closed tab item with parameters needed to restore it, and
   // add it to the menumodel at |curr_model_index|.
   void BuildLocalTabItem(int seesion_id,
-                         const string16& title,
+                         const base::string16& title,
                          const GURL& url,
                          int curr_model_index);
 
diff --git a/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model_unittest.cc b/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model_unittest.cc
index 366bbfa..97b27ae 100644
--- a/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model_unittest.cc
+++ b/chrome/browser/ui/toolbar/recent_tabs_sub_menu_model_unittest.cc
@@ -146,7 +146,7 @@ TEST_F(RecentTabsSubMenuModelTest, NoTabs) {
   EXPECT_EQ(NULL, model.GetLabelFontAt(2));
 
   std::string url;
-  string16 title;
+  base::string16 title;
   EXPECT_FALSE(model.GetURLAndTitleForItemAtIndex(0, &url, &title));
   EXPECT_FALSE(model.GetURLAndTitleForItemAtIndex(1, &url, &title));
   EXPECT_FALSE(model.GetURLAndTitleForItemAtIndex(2, &url, &title));
@@ -189,7 +189,7 @@ TEST_F(RecentTabsSubMenuModelTest, RecentlyClosedTabsFromCurrentSession) {
   EXPECT_EQ(NULL, model.GetLabelFontAt(4));
 
   std::string url;
-  string16 title;
+  base::string16 title;
   EXPECT_FALSE(model.GetURLAndTitleForItemAtIndex(0, &url, &title));
   EXPECT_TRUE(model.GetURLAndTitleForItemAtIndex(1, &url, &title));
   EXPECT_TRUE(model.GetURLAndTitleForItemAtIndex(2, &url, &title));
@@ -300,7 +300,7 @@ TEST_F(RecentTabsSubMenuModelTest,
   EXPECT_EQ(NULL, model.GetLabelFontAt(5));
 
   std::string url;
-  string16 title;
+  base::string16 title;
   EXPECT_FALSE(model.GetURLAndTitleForItemAtIndex(0, &url, &title));
   EXPECT_FALSE(model.GetURLAndTitleForItemAtIndex(1, &url, &title));
   EXPECT_TRUE(model.GetURLAndTitleForItemAtIndex(2, &url, &title));
@@ -323,7 +323,7 @@ TEST_F(RecentTabsSubMenuModelTest, OtherDevices) {
   recent_tabs_builder.AddWindow(0);
   for (int i = 0; i < 3; ++i) {
     timestamp -= time_delta;
-    recent_tabs_builder.AddTabWithInfo(0, 0, timestamp, string16());
+    recent_tabs_builder.AddTabWithInfo(0, 0, timestamp, base::string16());
   }
 
   // Create 2nd session : 2 windows, 1 tab in 1st window, 2 tabs in 2nd window
@@ -331,11 +331,11 @@ TEST_F(RecentTabsSubMenuModelTest, OtherDevices) {
   recent_tabs_builder.AddWindow(1);
   recent_tabs_builder.AddWindow(1);
   timestamp -= time_delta;
-  recent_tabs_builder.AddTabWithInfo(1, 0, timestamp, string16());
+  recent_tabs_builder.AddTabWithInfo(1, 0, timestamp, base::string16());
   timestamp -= time_delta;
-  recent_tabs_builder.AddTabWithInfo(1, 1, timestamp, string16());
+  recent_tabs_builder.AddTabWithInfo(1, 1, timestamp, base::string16());
   timestamp -= time_delta;
-  recent_tabs_builder.AddTabWithInfo(1, 1, timestamp, string16());
+  recent_tabs_builder.AddTabWithInfo(1, 1, timestamp, base::string16());
 
   recent_tabs_builder.RegisterRecentTabs(&associator_);
 
@@ -391,7 +391,7 @@ TEST_F(RecentTabsSubMenuModelTest, OtherDevices) {
   EXPECT_EQ(NULL, model.GetLabelFontAt(12));
 
   std::string url;
-  string16 title;
+  base::string16 title;
   EXPECT_FALSE(model.GetURLAndTitleForItemAtIndex(0, &url, &title));
   EXPECT_FALSE(model.GetURLAndTitleForItemAtIndex(1, &url, &title));
   EXPECT_FALSE(model.GetURLAndTitleForItemAtIndex(2, &url, &title));
diff --git a/chrome/browser/ui/toolbar/test_toolbar_model.cc b/chrome/browser/ui/toolbar/test_toolbar_model.cc
index d1d558c..67a1756 100644
--- a/chrome/browser/ui/toolbar/test_toolbar_model.cc
+++ b/chrome/browser/ui/toolbar/test_toolbar_model.cc
@@ -20,7 +20,7 @@ string16 TestToolbarModel::GetText() const {
 }
 
 string16 TestToolbarModel::GetCorpusNameForMobile() const {
-  return string16();
+  return base::string16();
 }
 
 GURL TestToolbarModel::GetURL() const {
diff --git a/chrome/browser/ui/toolbar/test_toolbar_model.h b/chrome/browser/ui/toolbar/test_toolbar_model.h
index 79887c5..40261e2 100644
--- a/chrome/browser/ui/toolbar/test_toolbar_model.h
+++ b/chrome/browser/ui/toolbar/test_toolbar_model.h
@@ -16,17 +16,17 @@ class TestToolbarModel : public ToolbarModel {
  public:
   TestToolbarModel();
   virtual ~TestToolbarModel();
-  virtual string16 GetText() const OVERRIDE;
-  virtual string16 GetCorpusNameForMobile() const OVERRIDE;
+  virtual base::string16 GetText() const OVERRIDE;
+  virtual base::string16 GetCorpusNameForMobile() const OVERRIDE;
   virtual GURL GetURL() const OVERRIDE;
   virtual bool WouldPerformSearchTermReplacement(
       bool ignore_editing) const OVERRIDE;
   virtual SecurityLevel GetSecurityLevel(bool ignore_editing) const OVERRIDE;
   virtual int GetIcon() const OVERRIDE;
-  virtual string16 GetEVCertName() const OVERRIDE;
+  virtual base::string16 GetEVCertName() const OVERRIDE;
   virtual bool ShouldDisplayURL() const OVERRIDE;
 
-  void set_text(const string16& text) { text_ = text; }
+  void set_text(const base::string16& text) { text_ = text; }
   void set_url(const GURL& url) { url_ = url;}
   void set_replace_search_url_with_search_terms(bool should_replace_url) {
     should_replace_url_ = should_replace_url;
@@ -35,7 +35,7 @@ class TestToolbarModel : public ToolbarModel {
     security_level_ = security_level;
   }
   void set_icon(int icon) { icon_ = icon; }
-  void set_ev_cert_name(const string16& ev_cert_name) {
+  void set_ev_cert_name(const base::string16& ev_cert_name) {
     ev_cert_name_ = ev_cert_name;
   }
   void set_should_display_url(bool should_display_url) {
@@ -43,12 +43,12 @@ class TestToolbarModel : public ToolbarModel {
   }
 
  private:
-  string16 text_;
+  base::string16 text_;
   GURL url_;
   bool should_replace_url_;
   SecurityLevel security_level_;
   int icon_;
-  string16 ev_cert_name_;
+  base::string16 ev_cert_name_;
   bool should_display_url_;
 
   DISALLOW_COPY_AND_ASSIGN(TestToolbarModel);
diff --git a/chrome/browser/ui/toolbar/toolbar_model.h b/chrome/browser/ui/toolbar/toolbar_model.h
index 949764f..f815a53 100644
--- a/chrome/browser/ui/toolbar/toolbar_model.h
+++ b/chrome/browser/ui/toolbar/toolbar_model.h
@@ -37,14 +37,14 @@ class ToolbarModel {
   //   - The scheme and/or trailing slash may be dropped.
   //   - If the current page's URL is a search URL for the user's default search
   //     engine, the query will be extracted and returned.
-  virtual string16 GetText() const = 0;
+  virtual base::string16 GetText() const = 0;
 
   // Some search URLs bundle a special "corpus" param that we can extract and
   // display next to users' search terms in cases where we'd show the search
   // terms instead of the URL anyway.  For example, a Google image search might
   // show the corpus "Images:" plus a search string.  This is only used on
   // mobile.
-  virtual string16 GetCorpusNameForMobile() const = 0;
+  virtual base::string16 GetCorpusNameForMobile() const = 0;
 
   // Returns the URL of the current navigation entry.
   virtual GURL GetURL() const = 0;
@@ -68,7 +68,7 @@ class ToolbarModel {
 
   // Returns the name of the EV cert holder.  Only call this when the security
   // level is EV_SECURE.
-  virtual string16 GetEVCertName() const = 0;
+  virtual base::string16 GetEVCertName() const = 0;
 
   // Returns whether the URL for the current navigation entry should be
   // in the location bar.
diff --git a/chrome/browser/ui/toolbar/toolbar_model_impl.cc b/chrome/browser/ui/toolbar/toolbar_model_impl.cc
index 3fc3bd1..c7961a0 100644
--- a/chrome/browser/ui/toolbar/toolbar_model_impl.cc
+++ b/chrome/browser/ui/toolbar/toolbar_model_impl.cc
@@ -95,8 +95,8 @@ ToolbarModel::SecurityLevel ToolbarModelImpl::GetSecurityLevelForWebContents(
 }
 
 // ToolbarModelImpl Implementation.
-string16 ToolbarModelImpl::GetText() const {
-  string16 search_terms(GetSearchTerms(false));
+base::string16 ToolbarModelImpl::GetText() const {
+  base::string16 search_terms(GetSearchTerms(false));
   if (!search_terms.empty())
     return search_terms;
 
@@ -116,9 +116,9 @@ string16 ToolbarModelImpl::GetText() const {
                           net::UnescapeRule::NORMAL, NULL, NULL, NULL));
 }
 
-string16 ToolbarModelImpl::GetCorpusNameForMobile() const {
+base::string16 ToolbarModelImpl::GetCorpusNameForMobile() const {
   if (!WouldPerformSearchTermReplacement(false))
-    return string16();
+    return base::string16();
   GURL url(GetURL());
   // If there is a query in the url fragment look for the corpus name there,
   // otherwise look for the corpus name in the query parameters.
@@ -134,7 +134,7 @@ string16 ToolbarModelImpl::GetCorpusNameForMobile() const {
           net::UnescapeRule::NORMAL, NULL);
     }
   }
-  return string16();
+  return base::string16();
 }
 
 GURL ToolbarModelImpl::GetURL() const {
@@ -211,7 +211,7 @@ int ToolbarModelImpl::GetIcon() const {
   return icon_ids[GetSecurityLevel(false)];
 }
 
-string16 ToolbarModelImpl::GetEVCertName() const {
+base::string16 ToolbarModelImpl::GetEVCertName() const {
   DCHECK_EQ(EV_SECURE, GetSecurityLevel(false));
   scoped_refptr<net::X509Certificate> cert;
   // Note: Navigation controller and active entry are guaranteed non-NULL or
@@ -222,12 +222,13 @@ string16 ToolbarModelImpl::GetEVCertName() const {
 }
 
 // static
-string16 ToolbarModelImpl::GetEVCertName(const net::X509Certificate& cert) {
+base::string16 ToolbarModelImpl::GetEVCertName(
+    const net::X509Certificate& cert) {
   // EV are required to have an organization name and country.
   if (cert.subject().organization_names.empty() ||
       cert.subject().country_name.empty()) {
     NOTREACHED();
-    return string16();
+    return base::string16();
   }
 
   return l10n_util::GetStringFUTF16(
@@ -251,15 +252,17 @@ Profile* ToolbarModelImpl::GetProfile() const {
       NULL;
 }
 
-string16 ToolbarModelImpl::GetSearchTerms(bool ignore_editing) const {
+base::string16 ToolbarModelImpl::GetSearchTerms(bool ignore_editing) const {
   if (!search_term_replacement_enabled() ||
       (input_in_progress() && !ignore_editing))
-    return string16();
+    return base::string16();
 
   const WebContents* web_contents = delegate_->GetActiveWebContents();
-  string16 search_terms(chrome::GetSearchTerms(web_contents));
-  if (search_terms.empty())
-    return string16();  // We mainly do this to enforce the subsequent DCHECK.
+  base::string16 search_terms(chrome::GetSearchTerms(web_contents));
+  if (search_terms.empty()) {
+    // We mainly do this to enforce the subsequent DCHECK.
+    return base::string16();
+  }
 
   // If the page is still loading and the security style is unknown, consider
   // the page secure.  Without this, after the user hit enter on some search
@@ -283,5 +286,5 @@ string16 ToolbarModelImpl::GetSearchTerms(bool ignore_editing) const {
   // error.
   ToolbarModel::SecurityLevel security_level = GetSecurityLevel(ignore_editing);
   return ((security_level == NONE) || (security_level == SECURITY_ERROR)) ?
-      string16() : search_terms;
+      base::string16() : search_terms;
 }
diff --git a/chrome/browser/ui/toolbar/toolbar_model_impl.h b/chrome/browser/ui/toolbar/toolbar_model_impl.h
index d7dccb7..b25b7ee 100644
--- a/chrome/browser/ui/toolbar/toolbar_model_impl.h
+++ b/chrome/browser/ui/toolbar/toolbar_model_impl.h
@@ -37,18 +37,18 @@ class ToolbarModelImpl : public ToolbarModel {
       content::WebContents* web_contents);
 
   // Overriden from ToolbarModel.
-  virtual string16 GetText() const OVERRIDE;
-  virtual string16 GetCorpusNameForMobile() const OVERRIDE;
+  virtual base::string16 GetText() const OVERRIDE;
+  virtual base::string16 GetCorpusNameForMobile() const OVERRIDE;
   virtual GURL GetURL() const OVERRIDE;
   virtual bool WouldPerformSearchTermReplacement(
       bool ignore_editing) const OVERRIDE;
   virtual SecurityLevel GetSecurityLevel(bool ignore_editing) const OVERRIDE;
   virtual int GetIcon() const OVERRIDE;
-  virtual string16 GetEVCertName() const OVERRIDE;
+  virtual base::string16 GetEVCertName() const OVERRIDE;
   virtual bool ShouldDisplayURL() const OVERRIDE;
 
   // Returns "<organization_name> [<country>]".
-  static string16 GetEVCertName(const net::X509Certificate& cert);
+  static base::string16 GetEVCertName(const net::X509Certificate& cert);
 
  private:
   // Returns the navigation controller used to retrieve the navigation entry
@@ -63,7 +63,7 @@ class ToolbarModelImpl : public ToolbarModel {
   // appear in the omnibox (i.e. the page is sufficiently secure, search term
   // replacement is enabled, editing is not in progress, etc.).  If
   // |ignore_editing| is true, the "editing not in progress" check is skipped.
-  string16 GetSearchTerms(bool ignore_editing) const;
+  base::string16 GetSearchTerms(bool ignore_editing) const;
 
   ToolbarModelDelegate* delegate_;
 
diff --git a/chrome/browser/ui/toolbar/toolbar_model_unittest.cc b/chrome/browser/ui/toolbar/toolbar_model_unittest.cc
index d0e72db..11ac46a 100644
--- a/chrome/browser/ui/toolbar/toolbar_model_unittest.cc
+++ b/chrome/browser/ui/toolbar/toolbar_model_unittest.cc
@@ -34,9 +34,9 @@ namespace {
 struct TestItem {
   GURL url;
   // The expected text to display when query extraction is inactive.
-  string16 expected_replace_text_inactive;
+  base::string16 expected_replace_text_inactive;
   // The expected text to display when query extraction is active.
-  string16 expected_replace_text_active;
+  base::string16 expected_replace_text_active;
   bool would_perform_search_term_replacement;
   bool should_display_url;
 } test_items[] = {
@@ -63,8 +63,8 @@ struct TestItem {
   },
   {
     GURL("chrome-internal://newtab/"),
-    string16(),
-    string16(),
+    base::string16(),
+    base::string16(),
     false,
     false
   },
@@ -141,7 +141,7 @@ class ToolbarModelTest : public BrowserWithTestWindowTest {
 
  protected:
   void NavigateAndCheckText(const GURL& url,
-                            const string16& expected_text,
+                            const base::string16& expected_text,
                             bool would_perform_search_term_replacement,
                             bool should_display_url);
 
@@ -166,7 +166,7 @@ void ToolbarModelTest::SetUp() {
 
 void ToolbarModelTest::NavigateAndCheckText(
     const GURL& url,
-    const string16& expected_text,
+    const base::string16& expected_text,
     bool would_perform_search_term_replacement,
     bool should_display_url) {
   // Check while loading.
diff --git a/chrome/browser/ui/toolbar/wrench_menu_model.cc b/chrome/browser/ui/toolbar/wrench_menu_model.cc
index 63de978..1fae222 100644
--- a/chrome/browser/ui/toolbar/wrench_menu_model.cc
+++ b/chrome/browser/ui/toolbar/wrench_menu_model.cc
@@ -115,7 +115,7 @@ void EncodingMenuModel::Build() {
       encoding_menu_items.begin();
   for (; it != encoding_menu_items.end(); ++it) {
     int id = it->first;
-    string16& label = it->second;
+    base::string16& label = it->second;
     if (id == 0) {
       AddSeparator(ui::NORMAL_SEPARATOR);
     } else {
@@ -315,7 +315,7 @@ string16 WrenchMenuModel::GetLabelForCommandId(int command_id) const {
           browser_->profile()->GetOriginalProfile());
     default:
       NOTREACHED();
-      return string16();
+      return base::string16();
   }
 }
 
@@ -611,7 +611,7 @@ void WrenchMenuModel::Build(bool is_new_menu) {
   SigninManager* signin = SigninManagerFactory::GetForProfile(
       browser_->profile()->GetOriginalProfile());
   if (signin && signin->IsSigninAllowed()) {
-    const string16 short_product_name =
+    const base::string16 short_product_name =
         l10n_util::GetStringUTF16(IDS_SHORT_PRODUCT_NAME);
     AddItem(IDC_SHOW_SYNC_SETUP, l10n_util::GetStringFUTF16(
         IDS_SYNC_MENU_PRE_SYNCED_LABEL, short_product_name));
diff --git a/chrome/browser/ui/toolbar/wrench_menu_model.h b/chrome/browser/ui/toolbar/wrench_menu_model.h
index 159b219..9d38635 100644
--- a/chrome/browser/ui/toolbar/wrench_menu_model.h
+++ b/chrome/browser/ui/toolbar/wrench_menu_model.h
@@ -100,7 +100,7 @@ class WrenchMenuModel : public ui::SimpleMenuModel,
 
   // Overridden for both ButtonMenuItemModel::Delegate and SimpleMenuModel:
   virtual bool IsItemForCommandIdDynamic(int command_id) const OVERRIDE;
-  virtual string16 GetLabelForCommandId(int command_id) const OVERRIDE;
+  virtual base::string16 GetLabelForCommandId(int command_id) const OVERRIDE;
   virtual bool GetIconForCommandId(int command_id,
                                    gfx::Image* icon) const OVERRIDE;
   virtual void ExecuteCommand(int command_id, int event_flags) OVERRIDE;
@@ -167,7 +167,7 @@ class WrenchMenuModel : public ui::SimpleMenuModel,
   scoped_ptr<ui::ButtonMenuItemModel> zoom_menu_item_model_;
 
   // Label of the zoom label in the zoom menu item.
-  string16 zoom_label_;
+  base::string16 zoom_label_;
 
   // Tools menu.
   scoped_ptr<ToolsMenuModel> tools_menu_model_;
diff --git a/chrome/browser/ui/toolbar/wrench_menu_model_unittest.cc b/chrome/browser/ui/toolbar/wrench_menu_model_unittest.cc
index 3860ea8..c4de4ea 100644
--- a/chrome/browser/ui/toolbar/wrench_menu_model_unittest.cc
+++ b/chrome/browser/ui/toolbar/wrench_menu_model_unittest.cc
@@ -35,7 +35,7 @@ class MenuError : public GlobalError {
 
   virtual bool HasMenuItem() OVERRIDE { return true; }
   virtual int MenuItemCommandID() OVERRIDE { return command_id_; }
-  virtual string16 MenuItemLabel() OVERRIDE { return string16(); }
+  virtual base::string16 MenuItemLabel() OVERRIDE { return base::string16(); }
   virtual void ExecuteMenuItem(Browser* browser) OVERRIDE { execute_count_++; }
 
   virtual bool HasBubbleView() OVERRIDE { return false; }
diff --git a/chrome/browser/ui/translate/language_combobox_model.h b/chrome/browser/ui/translate/language_combobox_model.h
index 4af7a69..4daa855 100644
--- a/chrome/browser/ui/translate/language_combobox_model.h
+++ b/chrome/browser/ui/translate/language_combobox_model.h
@@ -23,7 +23,7 @@ class LanguageComboboxModel : public ui::ComboboxModel {
 
   // Overridden from ui::ComboboxModel:
   virtual int GetItemCount() const OVERRIDE;
-  virtual string16 GetItemAt(int index) OVERRIDE;
+  virtual base::string16 GetItemAt(int index) OVERRIDE;
   virtual bool IsItemSeparatorAt(int index) OVERRIDE;
   virtual int GetDefaultIndex() const OVERRIDE;
 
diff --git a/chrome/browser/ui/translate/translate_bubble_model.h b/chrome/browser/ui/translate/translate_bubble_model.h
index 67af93d..85b6cec 100644
--- a/chrome/browser/ui/translate/translate_bubble_model.h
+++ b/chrome/browser/ui/translate/translate_bubble_model.h
@@ -53,7 +53,7 @@ class TranslateBubbleModel {
   virtual int GetNumberOfLanguages() const = 0;
 
   // Returns the displayable name for the language at |index|.
-  virtual string16 GetLanguageNameAt(int index) const = 0;
+  virtual base::string16 GetLanguageNameAt(int index) const = 0;
 
   // Returns the original language index.
   virtual int GetOriginalLanguageIndex() const = 0;
diff --git a/chrome/browser/ui/translate/translate_bubble_model_impl.h b/chrome/browser/ui/translate/translate_bubble_model_impl.h
index 7557168..094b706 100644
--- a/chrome/browser/ui/translate/translate_bubble_model_impl.h
+++ b/chrome/browser/ui/translate/translate_bubble_model_impl.h
@@ -27,7 +27,7 @@ class TranslateBubbleModelImpl : public TranslateBubbleModel {
   virtual void SetErrorType(TranslateErrors::Type error_type) OVERRIDE;
   virtual void GoBackFromAdvanced() OVERRIDE;
   virtual int GetNumberOfLanguages() const OVERRIDE;
-  virtual string16 GetLanguageNameAt(int index) const OVERRIDE;
+  virtual base::string16 GetLanguageNameAt(int index) const OVERRIDE;
   virtual int GetOriginalLanguageIndex() const OVERRIDE;
   virtual void UpdateOriginalLanguageIndex(int index) OVERRIDE;
   virtual int GetTargetLanguageIndex() const OVERRIDE;
diff --git a/chrome/browser/ui/validation_message_bubble.h b/chrome/browser/ui/validation_message_bubble.h
index 82f7b3d..be99808 100644
--- a/chrome/browser/ui/validation_message_bubble.h
+++ b/chrome/browser/ui/validation_message_bubble.h
@@ -25,8 +25,8 @@ class ValidationMessageBubble {
   static scoped_ptr<ValidationMessageBubble> CreateAndShow(
       content::RenderWidgetHost* widget_host,
       const gfx::Rect& anchor_in_root_view,
-      const string16& main_text,
-      const string16& sub_text);
+      const base::string16& main_text,
+      const base::string16& sub_text);
 
   // Close the window and destruct the object.
   virtual ~ValidationMessageBubble() {}
diff --git a/chrome/browser/ui/web_applications/web_app_ui.cc b/chrome/browser/ui/web_applications/web_app_ui.cc
index d0a1253..8cced49 100644
--- a/chrome/browser/ui/web_applications/web_app_ui.cc
+++ b/chrome/browser/ui/web_applications/web_app_ui.cc
@@ -299,7 +299,7 @@ void UpdateShortcutWorker::UpdateShortcutsOnFileThread() {
   CheckExistingShortcuts();
   if (!shortcut_files_.empty()) {
     // Generates app id from web app url and profile path.
-    string16 app_id = ShellIntegration::GetAppModelIdForProfile(
+    base::string16 app_id = ShellIntegration::GetAppModelIdForProfile(
         UTF8ToWide(web_app::GenerateApplicationNameFromURL(shortcut_info_.url)),
         profile_path_);