Replace some string16's with base namespace in chrome/browser

TBR=sky

Review URL: https://codereview.chromium.org/101953005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240126 0039d316-1c4b-4281-b951-d872f2087c98

102 files changed, 333 insertions, 312 deletions

diff --git a/chrome/browser/ui/webui/about_ui.cc b/chrome/browser/ui/webui/about_ui.cc
index 1733570..29c2f12 100644
--- a/chrome/browser/ui/webui/about_ui.cc
+++ b/chrome/browser/ui/webui/about_ui.cc
@@ -904,7 +904,7 @@ void AboutMemoryHandler::OnDetailsAvailable() {
   const std::vector<ProcessData>& browser_processes = processes();
 
   // Aggregate per-process data into browser summary data.
-  string16 log_string;
+  base::string16 log_string;
   for (size_t index = 0; index < browser_processes.size(); index++) {
     if (browser_processes[index].processes.empty())
       continue;
diff --git a/chrome/browser/ui/webui/certificate_viewer_webui.h b/chrome/browser/ui/webui/certificate_viewer_webui.h
index 410300d..f546b10 100644
--- a/chrome/browser/ui/webui/certificate_viewer_webui.h
+++ b/chrome/browser/ui/webui/certificate_viewer_webui.h
@@ -41,7 +41,7 @@ class CertificateViewerDialog : private ui::WebDialogDelegate {
  private:
   // Overridden from ui::WebDialogDelegate:
   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<content::WebUIMessageHandler*>* handlers) const OVERRIDE;
@@ -61,7 +61,7 @@ class CertificateViewerDialog : private ui::WebDialogDelegate {
   ConstrainedWebDialogDelegate* dialog_;
 
   // The title of the certificate viewer dialog, Certificate Viewer: CN.
-  string16 title_;
+  base::string16 title_;
 
   DISALLOW_COPY_AND_ASSIGN(CertificateViewerDialog);
 };
diff --git a/chrome/browser/ui/webui/chromeos/imageburner/imageburner_ui.cc b/chrome/browser/ui/webui/chromeos/imageburner/imageburner_ui.cc
index 08b3146..0a1c11f 100644
--- a/chrome/browser/ui/webui/chromeos/imageburner/imageburner_ui.cc
+++ b/chrome/browser/ui/webui/chromeos/imageburner/imageburner_ui.cc
@@ -142,7 +142,7 @@ class WebUIHandler
 
   // BurnController::Delegate override.
   virtual void OnDeviceTooSmall(int64 device_size) OVERRIDE {
-    string16 size;
+    base::string16 size;
     GetDataSizeText(device_size, &size);
     StringValue device_size_text(size);
     web_ui()->CallJavascriptFunction("browserBridge.reportDeviceTooSmall",
@@ -153,7 +153,7 @@ class WebUIHandler
   virtual void OnProgress(ProgressType progress_type,
                           int64 amount_finished,
                           int64 amount_total) OVERRIDE {
-    const string16 time_remaining_text =
+    const base::string16 time_remaining_text =
         l10n_util::GetStringUTF16(IDS_IMAGEBURN_PROGRESS_TIME_UNKNOWN);
     SendProgressSignal(progress_type, amount_finished, amount_total,
                        time_remaining_text);
@@ -165,7 +165,7 @@ class WebUIHandler
       int64 amount_finished,
       int64 amount_total,
       const base::TimeDelta& time_remaining) OVERRIDE {
-    const string16 time_remaining_text = l10n_util::GetStringFUTF16(
+    const base::string16 time_remaining_text = l10n_util::GetStringFUTF16(
         IDS_IMAGEBURN_DOWNLOAD_TIME_REMAINING,
         ui::TimeFormat::TimeRemaining(time_remaining));
     SendProgressSignal(progress_type, amount_finished, amount_total,
@@ -185,7 +185,7 @@ class WebUIHandler
  private:
   void CreateDiskValue(const disks::DiskMountManager::Disk& disk,
                        DictionaryValue* disk_value) {
-    string16 label = ASCIIToUTF16(disk.drive_label());
+    base::string16 label = ASCIIToUTF16(disk.drive_label());
     base::i18n::AdjustStringForLocaleDirection(&label);
     disk_value->SetString(std::string(kPropertyLabel), label);
     disk_value->SetString(std::string(kPropertyFilePath), disk.file_path());
@@ -235,7 +235,7 @@ class WebUIHandler
   void SendProgressSignal(ProgressType progress_type,
                           int64 amount_finished,
                           int64 amount_total,
-                          const string16& time_remaining_text) {
+                          const base::string16& time_remaining_text) {
     DictionaryValue progress;
     int progress_message_id = 0;
     switch (progress_type) {
@@ -257,7 +257,7 @@ class WebUIHandler
     progress.SetInteger("amountFinished", amount_finished);
     progress.SetInteger("amountTotal", amount_total);
     if (amount_total != 0) {
-      string16 progress_text;
+      base::string16 progress_text;
       GetProgressText(progress_message_id, amount_finished, amount_total,
                       &progress_text);
       progress.SetString("progressText", progress_text);
@@ -270,7 +270,7 @@ class WebUIHandler
   }
 
   // size_text should be previously created.
-  void GetDataSizeText(int64 size, string16* size_text) {
+  void GetDataSizeText(int64 size, base::string16* size_text) {
     *size_text = ui::FormatBytes(size);
     base::i18n::AdjustStringForLocaleDirection(size_text);
   }
@@ -279,10 +279,10 @@ class WebUIHandler
   void GetProgressText(int message_id,
                        int64 amount_finished,
                        int64 amount_total,
-                       string16* progress_text) {
-    string16 finished;
+                       base::string16* progress_text) {
+    base::string16 finished;
     GetDataSizeText(amount_finished, &finished);
-    string16 total;
+    base::string16 total;
     GetDataSizeText(amount_total, &total);
     *progress_text = l10n_util::GetStringFUTF16(message_id, finished, total);
   }
diff --git a/chrome/browser/ui/webui/chromeos/login/app_launch_splash_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/app_launch_splash_screen_handler.cc
index e95fa2e..aaf1913 100644
--- a/chrome/browser/ui/webui/chromeos/login/app_launch_splash_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/app_launch_splash_screen_handler.cc
@@ -57,7 +57,7 @@ void AppLaunchSplashScreenHandler::DeclareLocalizedValues(
   builder->Add("appStartMessage", IDS_APP_START_NETWORK_WAIT_MESSAGE);
   builder->Add("configureNetwork", IDS_APP_START_CONFIGURE_NETWORK);
 
-  const string16 product_os_name =
+  const base::string16 product_os_name =
       l10n_util::GetStringUTF16(IDS_SHORT_PRODUCT_OS_NAME);
   builder->Add(
       "shortcutInfo",
diff --git a/chrome/browser/ui/webui/chromeos/login/base_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/base_screen_handler.cc
index 2fd1450..d530039 100644
--- a/chrome/browser/ui/webui/chromeos/login/base_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/base_screen_handler.cc
@@ -22,7 +22,7 @@ void LocalizedValuesBuilder::Add(const std::string& key,
 }
 
 void LocalizedValuesBuilder::Add(const std::string& key,
-                                 const string16& message) {
+                                 const base::string16& message) {
   dict_->SetString(key, message);
 }
 
@@ -33,15 +33,15 @@ void LocalizedValuesBuilder::Add(const std::string& key, int message_id) {
 
 void LocalizedValuesBuilder::AddF(const std::string& key,
                                   int message_id,
-                                  const string16& a) {
+                                  const base::string16& a) {
   dict_->SetString(key,
                    l10n_util::GetStringFUTF16(message_id, a));
 }
 
 void LocalizedValuesBuilder::AddF(const std::string& key,
                                   int message_id,
-                                  const string16& a,
-                                  const string16& b) {
+                                  const base::string16& a,
+                                  const base::string16& b) {
   dict_->SetString(key,
                    l10n_util::GetStringFUTF16(message_id, a, b));
 }
diff --git a/chrome/browser/ui/webui/chromeos/login/base_screen_handler.h b/chrome/browser/ui/webui/chromeos/login/base_screen_handler.h
index 4baf62c..9efddca 100644
--- a/chrome/browser/ui/webui/chromeos/login/base_screen_handler.h
+++ b/chrome/browser/ui/webui/chromeos/login/base_screen_handler.h
@@ -34,7 +34,7 @@ class LocalizedValuesBuilder {
 
   // Method to declare localized value. |key| is the i18n key used in html.
   // |message| is text of the message.
-  void Add(const std::string& key, const string16& message);
+  void Add(const std::string& key, const base::string16& message);
 
   // Method to declare localized value. |key| is the i18n key used in html.
   // |message_id| is a resource id of message.
@@ -45,15 +45,15 @@ class LocalizedValuesBuilder {
   // one format parameter subsituted by |a|.
   void AddF(const std::string& key,
             int message_id,
-            const string16& a);
+            const base::string16& a);
 
   // Method to declare localized value. |key| is the i18n key used in html.
   // |message_id| is a resource id of message. Message is expected to have
   // two format parameters subsituted by |a| and |b| respectively.
   void AddF(const std::string& key,
             int message_id,
-            const string16& a,
-            const string16& b);
+            const base::string16& a,
+            const base::string16& b);
 
   // Method to declare localized value. |key| is the i18n key used in html.
   // |message_id| is a resource id of message. Message is expected to have
diff --git a/chrome/browser/ui/webui/chromeos/login/base_screen_handler_utils.h b/chrome/browser/ui/webui/chromeos/login/base_screen_handler_utils.h
index f39c82a..05bfaec 100644
--- a/chrome/browser/ui/webui/chromeos/login/base_screen_handler_utils.h
+++ b/chrome/browser/ui/webui/chromeos/login/base_screen_handler_utils.h
@@ -86,7 +86,7 @@ inline base::StringValue MakeValue(const std::string& v) {
   return base::StringValue(v);
 }
 
-inline base::StringValue MakeValue(const string16& v) {
+inline base::StringValue MakeValue(const base::string16& v) {
   return base::StringValue(v);
 }
 
diff --git a/chrome/browser/ui/webui/chromeos/login/locally_managed_user_creation_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/locally_managed_user_creation_screen_handler.cc
index 3952383..8d5f98a 100644
--- a/chrome/browser/ui/webui/chromeos/login/locally_managed_user_creation_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/locally_managed_user_creation_screen_handler.cc
@@ -219,7 +219,7 @@ void LocallyManagedUserCreationScreenHandler::ShowManagerPasswordError() {
 
 void LocallyManagedUserCreationScreenHandler::ShowStatusMessage(
     bool is_progress,
-    const string16& message) {
+    const base::string16& message) {
   if (is_progress)
     CallJS("showProgress", message);
   else
@@ -235,9 +235,9 @@ void LocallyManagedUserCreationScreenHandler::ShowTutorialPage() {
 }
 
 void LocallyManagedUserCreationScreenHandler::ShowErrorPage(
-    const string16& title,
-    const string16& message,
-    const string16& button_text) {
+    const base::string16& title,
+    const base::string16& message,
+    const base::string16& button_text) {
   CallJS("showErrorPage", title, message, button_text);
 }
 
@@ -269,7 +269,7 @@ void LocallyManagedUserCreationScreenHandler::HandleImportUserSelected(
 }
 
 void LocallyManagedUserCreationScreenHandler::HandleCheckLocallyManagedUserName(
-    const string16& name) {
+    const base::string16& name) {
   std::string user_id;
   if (NULL != UserManager::Get()->GetSupervisedUserManager()->
           FindByDisplayName(CollapseWhitespace(name, true))) {
@@ -289,11 +289,12 @@ void LocallyManagedUserCreationScreenHandler::HandleCheckLocallyManagedUserName(
 }
 
 void LocallyManagedUserCreationScreenHandler::HandleCreateManagedUser(
-    const string16& new_raw_user_name,
+    const base::string16& new_raw_user_name,
     const std::string& new_user_password) {
   if (!delegate_)
     return;
-  const string16 new_user_name = CollapseWhitespace(new_raw_user_name, true);
+  const base::string16 new_user_name =
+      CollapseWhitespace(new_raw_user_name, true);
   if (NULL != UserManager::Get()->GetSupervisedUserManager()->
           FindByDisplayName(new_user_name)) {
     CallJS("managedUserNameError", new_user_name,
diff --git a/chrome/browser/ui/webui/chromeos/login/locally_managed_user_creation_screen_handler.h b/chrome/browser/ui/webui/chromeos/login/locally_managed_user_creation_screen_handler.h
index 55673b2..8fcf3fb 100644
--- a/chrome/browser/ui/webui/chromeos/login/locally_managed_user_creation_screen_handler.h
+++ b/chrome/browser/ui/webui/chromeos/login/locally_managed_user_creation_screen_handler.h
@@ -38,13 +38,13 @@ class LocallyManagedUserCreationScreenHandler : public BaseScreenHandler {
     // Starts managed user creation flow, with supervised user that would have
     // |display_name| and authenticated by the |managed_user_password|.
     virtual void CreateManagedUser(
-        const string16& display_name,
+        const base::string16& display_name,
         const std::string& managed_user_password) = 0;
 
     // Look up if user with name |display_name| already exist and can be
     // imported. Returns user ID in |out_id|. Returns true if user was found,
     // false otherwise.
-    virtual bool FindUserByDisplayName(const string16& display_name,
+    virtual bool FindUserByDisplayName(const base::string16& display_name,
                                        std::string *out_id) const = 0;
 
     // Starts managed user import flow for user identified with |user_id|.
@@ -81,12 +81,12 @@ class LocallyManagedUserCreationScreenHandler : public BaseScreenHandler {
 
   // Shows progress or error message close in the button area. |is_progress| is
   // true for progress messages and false for error messages.
-  void ShowStatusMessage(bool is_progress, const string16& message);
+  void ShowStatusMessage(bool is_progress, const base::string16& message);
   void ShowTutorialPage();
 
-  void ShowErrorPage(const string16& title,
-                     const string16& message,
-                     const string16& button_text);
+  void ShowErrorPage(const base::string16& title,
+                     const base::string16& message,
+                     const base::string16& button_text);
 
   // Navigates to specified page.
   void ShowPage(const std::string& page);
@@ -104,7 +104,7 @@ class LocallyManagedUserCreationScreenHandler : public BaseScreenHandler {
 
  private:
   // WebUI message handlers.
-  void HandleCheckLocallyManagedUserName(const string16& name);
+  void HandleCheckLocallyManagedUserName(const base::string16& name);
 
   void HandleManagerSelected(const std::string& manager_id);
   void HandleImportUserSelected(const std::string& user_id);
@@ -116,7 +116,7 @@ class LocallyManagedUserCreationScreenHandler : public BaseScreenHandler {
 
   void HandleAuthenticateManager(const std::string& raw_manager_username,
                                  const std::string& manager_password);
-  void HandleCreateManagedUser(const string16& new_raw_user_name,
+  void HandleCreateManagedUser(const base::string16& new_raw_user_name,
                                const std::string& new_user_password);
   void HandleImportSupervisedUser(const std::string& user_id);
   void HandleImportSupervisedUserWithPassword(const std::string& user_id,
@@ -128,7 +128,7 @@ class LocallyManagedUserCreationScreenHandler : public BaseScreenHandler {
   void HandleSelectImage(const std::string& image_url,
                          const std::string& image_type);
 
-  void UpdateText(const std::string& element_id, const string16& text);
+  void UpdateText(const std::string& element_id, const base::string16& text);
 
   Delegate* delegate_;
 
diff --git a/chrome/browser/ui/webui/chromeos/login/network_dropdown.cc b/chrome/browser/ui/webui/chromeos/login/network_dropdown.cc
index e3d6728..5076cc4 100644
--- a/chrome/browser/ui/webui/chromeos/login/network_dropdown.cc
+++ b/chrome/browser/ui/webui/chromeos/login/network_dropdown.cc
@@ -181,7 +181,7 @@ void NetworkDropdown::Refresh() {
 }
 
 void NetworkDropdown::SetNetworkIconAndText() {
-  string16 text;
+  base::string16 text;
   gfx::ImageSkia icon_image;
   bool animating = false;
   ash::network_icon::GetDefaultNetworkImageAndLabel(
diff --git a/chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc
index 93531f3..603c5c2b 100644
--- a/chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/network_screen_handler.cc
@@ -78,7 +78,7 @@ void NetworkScreenHandler::Show() {
 void NetworkScreenHandler::Hide() {
 }
 
-void NetworkScreenHandler::ShowError(const string16& message) {
+void NetworkScreenHandler::ShowError(const base::string16& message) {
   CallJS("showError", message);
 }
 
@@ -89,8 +89,8 @@ void NetworkScreenHandler::ClearErrors() {
 
 void NetworkScreenHandler::ShowConnectingStatus(
     bool connecting,
-    const string16& network_id) {
-  // string16 connecting_label =
+    const base::string16& network_id) {
+  // base::string16 connecting_label =
   //     l10n_util::GetStringFUTF16(IDS_NETWORK_SELECTION_CONNECTING,
   //                                network_id);
   // CallJS("cr.ui.Oobe.showConnectingStatus",
diff --git a/chrome/browser/ui/webui/chromeos/login/network_screen_handler.h b/chrome/browser/ui/webui/chromeos/login/network_screen_handler.h
index a19486b..56cb8a2 100644
--- a/chrome/browser/ui/webui/chromeos/login/network_screen_handler.h
+++ b/chrome/browser/ui/webui/chromeos/login/network_screen_handler.h
@@ -32,10 +32,10 @@ class NetworkScreenHandler : public NetworkScreenActor,
   virtual void PrepareToShow() OVERRIDE;
   virtual void Show() OVERRIDE;
   virtual void Hide() OVERRIDE;
-  virtual void ShowError(const string16& message) OVERRIDE;
+  virtual void ShowError(const base::string16& message) OVERRIDE;
   virtual void ClearErrors() OVERRIDE;
   virtual void ShowConnectingStatus(bool connecting,
-                                    const string16& network_id) OVERRIDE;
+                                    const base::string16& network_id) OVERRIDE;
   virtual void EnableContinue(bool enabled) OVERRIDE;
 
   // BaseScreenHandler implementation:
diff --git a/chrome/browser/ui/webui/chromeos/mobile_setup_dialog.cc b/chrome/browser/ui/webui/chromeos/mobile_setup_dialog.cc
index 1ad3328..81b1851 100644
--- a/chrome/browser/ui/webui/chromeos/mobile_setup_dialog.cc
+++ b/chrome/browser/ui/webui/chromeos/mobile_setup_dialog.cc
@@ -44,7 +44,7 @@ class MobileSetupDialogDelegate : public WebDialogDelegate {
 
   // WebDialogDelegate overrides.
   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;
diff --git a/chrome/browser/ui/webui/chromeos/mobile_setup_ui.cc b/chrome/browser/ui/webui/chromeos/mobile_setup_ui.cc
index df644ab3..486ce96 100644
--- a/chrome/browser/ui/webui/chromeos/mobile_setup_ui.cc
+++ b/chrome/browser/ui/webui/chromeos/mobile_setup_ui.cc
@@ -635,7 +635,7 @@ MobileSetupUI::MobileSetupUI(content::WebUI* web_ui)
 
 void MobileSetupUI::DidCommitProvisionalLoadForFrame(
     int64 frame_id,
-    const string16& frame_unique_name,
+    const base::string16& frame_unique_name,
     bool is_main_frame,
     const GURL& url,
     content::PageTransition transition_type,
@@ -649,11 +649,11 @@ void MobileSetupUI::DidCommitProvisionalLoadForFrame(
 
 void MobileSetupUI::DidFailProvisionalLoad(
     int64 frame_id,
-    const string16& frame_unique_name,
+    const base::string16& frame_unique_name,
     bool is_main_frame,
     const GURL& validated_url,
     int error_code,
-    const string16& error_description,
+    const base::string16& error_description,
     content::RenderViewHost* render_view_host) {
   if (frame_unique_name != UTF8ToUTF16("paymentForm"))
     return;
diff --git a/chrome/browser/ui/webui/chromeos/mobile_setup_ui.h b/chrome/browser/ui/webui/chromeos/mobile_setup_ui.h
index 336d2fd..cbd5541 100644
--- a/chrome/browser/ui/webui/chromeos/mobile_setup_ui.h
+++ b/chrome/browser/ui/webui/chromeos/mobile_setup_ui.h
@@ -21,18 +21,18 @@ class MobileSetupUI : public content::WebUIController,
   // content::WebContentsObserver overrides.
   virtual void DidCommitProvisionalLoadForFrame(
       int64 frame_id,
-      const string16& frame_unique_name,
+      const base::string16& frame_unique_name,
       bool is_main_frame,
       const GURL& url,
       content::PageTransition transition_type,
       content::RenderViewHost* render_view_host) OVERRIDE;
   virtual void DidFailProvisionalLoad(
       int64 frame_id,
-      const string16& frame_unique_name,
+      const base::string16& frame_unique_name,
       bool is_main_frame,
       const GURL& validated_url,
       int error_code,
-      const string16& error_description,
+      const base::string16& error_description,
       content::RenderViewHost* render_view_host) OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(MobileSetupUI);
diff --git a/chrome/browser/ui/webui/conflicts_ui.cc b/chrome/browser/ui/webui/conflicts_ui.cc
index c5f0a19..cc937aa 100644
--- a/chrome/browser/ui/webui/conflicts_ui.cc
+++ b/chrome/browser/ui/webui/conflicts_ui.cc
@@ -121,7 +121,7 @@ void ConflictsDOMHandler::SendModuleList() {
   // Add the section title and the total count for bad modules found.
   int confirmed_bad = loaded_modules->confirmed_bad_modules_detected();
   int suspected_bad = loaded_modules->suspected_bad_modules_detected();
-  string16 table_title;
+  base::string16 table_title;
   if (!confirmed_bad && !suspected_bad) {
     table_title += l10n_util::GetStringFUTF16(
         IDS_CONFLICTS_CHECK_PAGE_TABLE_TITLE_SUFFIX_ONE,
diff --git a/chrome/browser/ui/webui/downloads_dom_handler.cc b/chrome/browser/ui/webui/downloads_dom_handler.cc
index f964d84..77f3c31 100644
--- a/chrome/browser/ui/webui/downloads_dom_handler.cc
+++ b/chrome/browser/ui/webui/downloads_dom_handler.cc
@@ -151,7 +151,7 @@ DictionaryValue* CreateDownloadItemValue(
   }
 
   // Keep file names as LTR.
-  string16 file_name =
+  base::string16 file_name =
     download_item->GetFileNameToReportUser().LossyDisplayName();
   file_name = base::i18n::GetDisplayStringInLTRDirectionality(file_name);
   file_value->SetString("file_name", file_name);
diff --git a/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc b/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc
index 39ae6a2..3fdaecf 100644
--- a/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc
+++ b/chrome/browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc
@@ -159,7 +159,7 @@ void KioskAppsHandler::GetLocalizedValues(content::WebUIDataSource* source) {
       "kioskDisableBailoutShortcutWarningBold",
       l10n_util::GetStringUTF16(
           IDS_OPTIONS_KIOSK_DISABLE_BAILOUT_SHORTCUT_WARNING_BOLD));
-  const string16 product_os_name =
+  const base::string16 product_os_name =
       l10n_util::GetStringUTF16(IDS_SHORT_PRODUCT_OS_NAME);
   source->AddString(
       "kioskDisableBailoutShortcutWarning",
diff --git a/chrome/browser/ui/webui/extensions/extension_settings_handler.cc b/chrome/browser/ui/webui/extensions/extension_settings_handler.cc
index 7fbafa6..1a757c0 100644
--- a/chrome/browser/ui/webui/extensions/extension_settings_handler.cc
+++ b/chrome/browser/ui/webui/extensions/extension_settings_handler.cc
@@ -233,7 +233,7 @@ base::DictionaryValue* ExtensionSettingsHandler::CreateExtensionDetailValue(
   extension_data->SetBoolean("homepageProvided",
       ManifestURL::GetHomepageURL(extension).is_valid());
 
-  string16 location_text;
+  base::string16 location_text;
   if (Manifest::IsPolicyLocation(extension->location())) {
     location_text = l10n_util::GetStringUTF16(
         IDS_OPTIONS_INSTALL_LOCATION_ENTERPRISE);
@@ -997,7 +997,7 @@ void ExtensionSettingsHandler::HandleLoadUnpackedExtensionMessage(
     const base::ListValue* args) {
   DCHECK(args->empty());
 
-  string16 select_title =
+  base::string16 select_title =
       l10n_util::GetStringUTF16(IDS_EXTENSION_LOAD_FROM_DIRECTORY);
 
   const int kFileTypeIndex = 0;  // No file type information to index.
diff --git a/chrome/browser/ui/webui/extensions/pack_extension_handler.cc b/chrome/browser/ui/webui/extensions/pack_extension_handler.cc
index 4bb3e4e..49f47c4 100644
--- a/chrome/browser/ui/webui/extensions/pack_extension_handler.cc
+++ b/chrome/browser/ui/webui/extensions/pack_extension_handler.cc
@@ -169,7 +169,7 @@ void PackExtensionHandler::HandleSelectFilePathMessage(
     path_to_use = base::FilePath();
   }
 
-  string16 select_title;
+  base::string16 select_title;
   if (operation == "load") {
     select_title = l10n_util::GetStringUTF16(IDS_EXTENSION_LOAD_FROM_DIRECTORY);
   } else if (operation == "pem") {
diff --git a/chrome/browser/ui/webui/flags_ui.cc b/chrome/browser/ui/webui/flags_ui.cc
index 405c7fd..c21350f 100644
--- a/chrome/browser/ui/webui/flags_ui.cc
+++ b/chrome/browser/ui/webui/flags_ui.cc
@@ -84,7 +84,7 @@ content::WebUIDataSource* CreateFlagsUIHTMLSource() {
   } else {
     // The warning will be only shown on ChromeOS, when the current user is not
     // the owner.
-    source->AddString("ownerWarning", string16());
+    source->AddString("ownerWarning", base::string16());
   }
 #endif
 
diff --git a/chrome/browser/ui/webui/flash_ui.cc b/chrome/browser/ui/webui/flash_ui.cc
index cf4aefb..4d6333c 100644
--- a/chrome/browser/ui/webui/flash_ui.cc
+++ b/chrome/browser/ui/webui/flash_ui.cc
@@ -180,14 +180,18 @@ void FlashDOMHandler::OnUploadListAvailable() {
   MaybeRespondToPage();
 }
 
-void AddPair(ListValue* list, const string16& key, const string16& value) {
+void AddPair(ListValue* list,
+             const base::string16& key,
+             const base::string16& value) {
   DictionaryValue* results = new DictionaryValue();
   results->SetString("key", key);
   results->SetString("value", value);
   list->Append(results);
 }
 
-void AddPair(ListValue* list, const string16& key, const std::string& value) {
+void AddPair(ListValue* list,
+             const base::string16& key,
+             const std::string& value) {
   AddPair(list, key, ASCIIToUTF16(value));
 }
 
@@ -275,7 +279,7 @@ void FlashDOMHandler::MaybeRespondToPage() {
         PluginPrefs::GetForProfile(Profile::FromWebUI(web_ui())).get();
     bool found_enabled = false;
     for (size_t i = 0; i < info_array.size(); ++i) {
-      string16 flash_version = info_array[i].version + ASCIIToUTF16(" ") +
+      base::string16 flash_version = info_array[i].version + ASCIIToUTF16(" ") +
                                info_array[i].path.LossyDisplayName();
       if (plugin_prefs->IsPluginEnabled(info_array[i])) {
         // If we have already found an enabled Flash version, this one
@@ -292,7 +296,7 @@ void FlashDOMHandler::MaybeRespondToPage() {
   }
 
   // Crash information.
-  AddPair(list, string16(), "--- Crash data ---");
+  AddPair(list, base::string16(), "--- Crash data ---");
   bool crash_reporting_enabled = CrashesUI::CrashReportingUIEnabled();
   if (crash_reporting_enabled) {
     std::vector<CrashUploadList::UploadInfo> crashes;
@@ -300,7 +304,7 @@ void FlashDOMHandler::MaybeRespondToPage() {
 
     for (std::vector<CrashUploadList::UploadInfo>::iterator i = crashes.begin();
          i != crashes.end(); ++i) {
-      string16 crash_string(ASCIIToUTF16(i->id));
+      base::string16 crash_string(ASCIIToUTF16(i->id));
       crash_string += ASCIIToUTF16(" ");
       crash_string += base::TimeFormatFriendlyDateAndTime(i->time);
       AddPair(list, ASCIIToUTF16("crash id"), crash_string);
@@ -313,7 +317,7 @@ void FlashDOMHandler::MaybeRespondToPage() {
   }
 
   // GPU information.
-  AddPair(list, string16(), "--- GPU information ---");
+  AddPair(list, base::string16(), "--- GPU information ---");
   gpu::GPUInfo gpu_info = GpuDataManager::GetInstance()->GetGPUInfo();
 
   std::string reason;
@@ -344,7 +348,7 @@ void FlashDOMHandler::MaybeRespondToPage() {
   }
 #endif
 
-  AddPair(list, string16(), "--- GPU driver, more information ---");
+  AddPair(list, base::string16(), "--- GPU driver, more information ---");
   AddPair(list,
           ASCIIToUTF16("Vendor Id"),
           base::StringPrintf("0x%04x", gpu_info.gpu.vendor_id));
diff --git a/chrome/browser/ui/webui/help/help_handler.cc b/chrome/browser/ui/webui/help/help_handler.cc
index a42f63f..98c5202 100644
--- a/chrome/browser/ui/webui/help/help_handler.cc
+++ b/chrome/browser/ui/webui/help/help_handler.cc
@@ -227,19 +227,19 @@ void HelpHandler::GetLocalizedValues(content::WebUIDataSource* source) {
        l10n_util::GetStringFUTF16(IDS_ABOUT_VERSION_COPYRIGHT,
                                   base::IntToString16(exploded_time.year)));
 
-  string16 license = l10n_util::GetStringFUTF16(
+  base::string16 license = l10n_util::GetStringFUTF16(
       IDS_ABOUT_VERSION_LICENSE,
       ASCIIToUTF16(chrome::kChromiumProjectURL),
       ASCIIToUTF16(chrome::kChromeUICreditsURL));
   source->AddString("productLicense", license);
 
 #if defined(OS_CHROMEOS)
-  string16 os_license = l10n_util::GetStringFUTF16(
+  base::string16 os_license = l10n_util::GetStringFUTF16(
       IDS_ABOUT_CROS_VERSION_LICENSE,
       ASCIIToUTF16(chrome::kChromeUIOSCreditsURL));
   source->AddString("productOsLicense", os_license);
 
-  string16 product_name = l10n_util::GetStringUTF16(IDS_PRODUCT_OS_NAME);
+  base::string16 product_name = l10n_util::GetStringUTF16(IDS_PRODUCT_OS_NAME);
   source->AddString(
       "channelChangePageDelayedChangeMessage",
       l10n_util::GetStringFUTF16(
@@ -257,7 +257,7 @@ void HelpHandler::GetLocalizedValues(content::WebUIDataSource* source) {
   }
 #endif
 
-  string16 tos = l10n_util::GetStringFUTF16(
+  base::string16 tos = l10n_util::GetStringFUTF16(
       IDS_ABOUT_TERMS_OF_SERVICE, UTF8ToUTF16(chrome::kChromeUITermsURL));
   source->AddString("productTOS", tos);
 
@@ -332,7 +332,7 @@ void HelpHandler::OnPageLoaded(const ListValue* args) {
       base::FundamentalValue(CanChangeChannel()));
 
   base::Time build_time = base::SysInfo::GetLsbReleaseTime();
-  string16 build_date = base::TimeFormatFriendlyDate(build_time);
+  base::string16 build_date = base::TimeFormatFriendlyDate(build_time);
   web_ui()->CallJavascriptFunction("help.HelpPage.setBuildDate",
                                    base::StringValue(build_date));
 #endif  // defined(OS_CHROMEOS)
@@ -427,7 +427,7 @@ void HelpHandler::RelaunchAndPowerwash(const ListValue* args) {
 #endif  // defined(OS_CHROMEOS)
 
 void HelpHandler::SetUpdateStatus(VersionUpdater::Status status,
-                                  int progress, const string16& message) {
+                                  int progress, const base::string16& message) {
   // Only UPDATING state should have progress set.
   DCHECK(status == VersionUpdater::UPDATING || progress == 0);
 
@@ -467,7 +467,7 @@ void HelpHandler::SetUpdateStatus(VersionUpdater::Status status,
 #if defined(OS_CHROMEOS)
   if (status == VersionUpdater::FAILED_OFFLINE ||
       status == VersionUpdater::FAILED_CONNECTION_TYPE_DISALLOWED) {
-    string16 types_msg = GetAllowedConnectionTypesMessage();
+    base::string16 types_msg = GetAllowedConnectionTypesMessage();
     if (!types_msg.empty()) {
       web_ui()->CallJavascriptFunction(
           "help.HelpPage.setAndShowAllowedConnectionTypesMsg",
diff --git a/chrome/browser/ui/webui/help/help_handler.h b/chrome/browser/ui/webui/help/help_handler.h
index 4131eb0..206f535 100644
--- a/chrome/browser/ui/webui/help/help_handler.h
+++ b/chrome/browser/ui/webui/help/help_handler.h
@@ -68,7 +68,7 @@ class HelpHandler : public content::WebUIMessageHandler,
 
   // Callback method which forwards status updates to the page.
   void SetUpdateStatus(VersionUpdater::Status status, int progress,
-                       const string16& fail_message);
+                       const base::string16& fail_message);
 
 #if defined(OS_MACOSX)
   // Callback method which forwards promotion state to the page.
diff --git a/chrome/browser/ui/webui/help/help_utils_chromeos.cc b/chrome/browser/ui/webui/help/help_utils_chromeos.cc
index 3cd29f1..8b30a39 100644
--- a/chrome/browser/ui/webui/help/help_utils_chromeos.cc
+++ b/chrome/browser/ui/webui/help/help_utils_chromeos.cc
@@ -61,7 +61,7 @@ string16 GetConnectionTypeAsUTF16(const std::string& type) {
   if (type == shill::kTypeVPN)
     return l10n_util::GetStringUTF16(IDS_NETWORK_TYPE_VPN);
   NOTREACHED();
-  return string16();
+  return base::string16();
 }
 
 }  // namespace help_utils_chromeos
diff --git a/chrome/browser/ui/webui/help/version_updater.h b/chrome/browser/ui/webui/help/version_updater.h
index a78444d..190ada7 100644
--- a/chrome/browser/ui/webui/help/version_updater.h
+++ b/chrome/browser/ui/webui/help/version_updater.h
@@ -41,9 +41,9 @@ class VersionUpdater {
 #endif
 
   // Used to update the client of status changes. int parameter is the progress
-  // and should only be non-zero for the UPDATING state.  string16 parameter is
-  // a message explaining a failure.
-  typedef base::Callback<void(Status, int, const string16&)>
+  // and should only be non-zero for the UPDATING state.
+  // base::string16 parameter is a message explaining a failure.
+  typedef base::Callback<void(Status, int, const base::string16&)>
       StatusCallback;
 
 #if defined(OS_MACOSX)
diff --git a/chrome/browser/ui/webui/help/version_updater_basic.cc b/chrome/browser/ui/webui/help/version_updater_basic.cc
index cb702aa..c0d0ee9 100644
--- a/chrome/browser/ui/webui/help/version_updater_basic.cc
+++ b/chrome/browser/ui/webui/help/version_updater_basic.cc
@@ -11,9 +11,9 @@
 void VersionUpdaterBasic::CheckForUpdate(
     const StatusCallback& status_callback) {
   if (UpgradeDetector::GetInstance()->notify_upgrade())
-    status_callback.Run(NEARLY_UPDATED, 0, string16());
+    status_callback.Run(NEARLY_UPDATED, 0, base::string16());
   else
-    status_callback.Run(DISABLED, 0, string16());
+    status_callback.Run(DISABLED, 0, base::string16());
 }
 
 void VersionUpdaterBasic::RelaunchBrowser() const {
diff --git a/chrome/browser/ui/webui/help/version_updater_chromeos.cc b/chrome/browser/ui/webui/help/version_updater_chromeos.cc
index b1362dd..74a475e 100644
--- a/chrome/browser/ui/webui/help/version_updater_chromeos.cc
+++ b/chrome/browser/ui/webui/help/version_updater_chromeos.cc
@@ -102,7 +102,7 @@ void VersionUpdaterCros::CheckForUpdate(const StatusCallback& callback) {
                   l10n_util::GetStringUTF16(IDS_UPGRADE_OFFLINE));
     return;
   } else if (status == NETWORK_STATUS_DISALLOWED) {
-    string16 message =
+    base::string16 message =
         l10n_util::GetStringFUTF16(
             IDS_UPGRADE_DISALLOWED,
             help_utils_chromeos::GetConnectionTypeAsUTF16(network->type()));
@@ -161,7 +161,7 @@ void VersionUpdaterCros::UpdateStatusChanged(
     const UpdateEngineClient::Status& status) {
   Status my_status = UPDATED;
   int progress = 0;
-  string16 message;
+  base::string16 message;
 
   // If the updater is currently idle, just show the last operation (unless it
   // was previously checking for an update -- in that case, the system is
@@ -213,5 +213,5 @@ void VersionUpdaterCros::OnUpdateCheck(
   // If version updating is not implemented, this binary is the most up-to-date
   // possible with respect to automatic updating.
   if (result == UpdateEngineClient::UPDATE_RESULT_NOTIMPLEMENTED)
-    callback_.Run(UPDATED, 0, string16());
+    callback_.Run(UPDATED, 0, base::string16());
 }
diff --git a/chrome/browser/ui/webui/help/version_updater_mac.mm b/chrome/browser/ui/webui/help/version_updater_mac.mm
index 331fe57..6b25716 100644
--- a/chrome/browser/ui/webui/help/version_updater_mac.mm
+++ b/chrome/browser/ui/webui/help/version_updater_mac.mm
@@ -102,7 +102,7 @@ void VersionUpdaterMac::CheckForUpdate(
   } else {
     // There is no glue, or the application is on a read-only filesystem.
     // Updates and promotions are impossible.
-    status_callback_.Run(DISABLED, 0, string16());
+    status_callback_.Run(DISABLED, 0, base::string16());
   }
 }
 
@@ -132,7 +132,7 @@ void VersionUpdaterMac::UpdateStatus(NSDictionary* dictionary) {
       [[dictionary objectForKey:kAutoupdateStatusStatus] intValue]);
 
   bool enable_promote_button = true;
-  string16 message;
+  base::string16 message;
 
   Status status;
   switch (keystone_status) {
@@ -198,9 +198,10 @@ void VersionUpdaterMac::UpdateStatus(NSDictionary* dictionary) {
     case kAutoupdateNeedsPromotion:
       {
         status = FAILED;
-        string16 product_name = l10n_util::GetStringUTF16(IDS_PRODUCT_NAME);
-        message = l10n_util:: GetStringFUTF16(IDS_PROMOTE_INFOBAR_TEXT,
-                                              product_name);
+        base::string16 product_name =
+            l10n_util::GetStringUTF16(IDS_PRODUCT_NAME);
+        message = l10n_util::GetStringFUTF16(IDS_PROMOTE_INFOBAR_TEXT,
+                                             product_name);
       }
       break;
 
diff --git a/chrome/browser/ui/webui/help/version_updater_win.cc b/chrome/browser/ui/webui/help/version_updater_win.cc
index 3d1a7ad..9491e10 100644
--- a/chrome/browser/ui/webui/help/version_updater_win.cc
+++ b/chrome/browser/ui/webui/help/version_updater_win.cc
@@ -47,13 +47,13 @@ class VersionUpdaterWin : public VersionUpdater,
   // GoogleUpdateStatusListener implementation.
   virtual void OnReportResults(GoogleUpdateUpgradeResult result,
                                GoogleUpdateErrorCode error_code,
-                               const string16& error_message,
-                               const string16& version) OVERRIDE;
+                               const base::string16& error_message,
+                               const base::string16& version) OVERRIDE;
 
   // Update the UI to show the status of the upgrade.
   void UpdateStatus(GoogleUpdateUpgradeResult result,
                     GoogleUpdateErrorCode error_code,
-                    const string16& error_message);
+                    const base::string16& error_message);
 
   // Got the intalled version so the handling of the UPGRADE_ALREADY_UP_TO_DATE
   // result case can now be completeb on the UI thread.
@@ -147,7 +147,8 @@ void VersionUpdaterWin::CheckForUpdate(const StatusCallback& callback) {
     // This could happen if the page got refreshed after results were returned.
     if (!google_updater_)
       CreateGoogleUpdater();
-    UpdateStatus(UPGRADE_CHECK_STARTED, GOOGLE_UPDATE_NO_ERROR, string16());
+    UpdateStatus(UPGRADE_CHECK_STARTED, GOOGLE_UPDATE_NO_ERROR,
+                 base::string16());
     // Specify false to not upgrade yet.
     google_updater_->CheckForUpdate(false, GetElevationParent());
   }
@@ -159,7 +160,7 @@ void VersionUpdaterWin::RelaunchBrowser() const {
 
 void VersionUpdaterWin::OnReportResults(
     GoogleUpdateUpgradeResult result, GoogleUpdateErrorCode error_code,
-    const string16& error_message, const string16& version) {
+    const base::string16& error_message, const base::string16& version) {
   // Drop the last reference to the object so that it gets cleaned up here.
   ClearGoogleUpdater();
   UpdateStatus(result, error_code, error_message);
@@ -167,13 +168,13 @@ void VersionUpdaterWin::OnReportResults(
 
 void VersionUpdaterWin::UpdateStatus(GoogleUpdateUpgradeResult result,
                                      GoogleUpdateErrorCode error_code,
-                                     const string16& error_message) {
+                                     const base::string16& error_message) {
   // For Chromium builds it would show an error message.
   // But it looks weird because in fact there is no error,
   // just the update server is not available for non-official builds.
 #if defined(GOOGLE_CHROME_BUILD)
   Status status = UPDATED;
-  string16 message;
+  base::string16 message;
 
   switch (result) {
     case UPGRADE_CHECK_STARTED: {
@@ -191,7 +192,7 @@ void VersionUpdaterWin::UpdateStatus(GoogleUpdateUpgradeResult result,
           UserMetricsAction("UpgradeCheck_UpgradeIsAvailable"));
       DCHECK(!google_updater_);  // Should have been nulled out already.
       CreateGoogleUpdater();
-      UpdateStatus(UPGRADE_STARTED, GOOGLE_UPDATE_NO_ERROR, string16());
+      UpdateStatus(UPGRADE_STARTED, GOOGLE_UPDATE_NO_ERROR, base::string16());
       // Specify true to upgrade now.
       google_updater_->CheckForUpdate(true, GetElevationParent());
       return;
@@ -255,10 +256,10 @@ void VersionUpdaterWin::GotInstalledVersion(const Version& version) {
   if (!version.IsValid() || version.CompareTo(running_version) <= 0) {
     content::RecordAction(
         UserMetricsAction("UpgradeCheck_AlreadyUpToDate"));
-    callback_.Run(UPDATED, 0, string16());
+    callback_.Run(UPDATED, 0, base::string16());
   } else {
     content::RecordAction(UserMetricsAction("UpgradeCheck_AlreadyUpgraded"));
-    callback_.Run(NEARLY_UPDATED, 0, string16());
+    callback_.Run(NEARLY_UPDATED, 0, base::string16());
   }
 }
 
diff --git a/chrome/browser/ui/webui/history_ui.cc b/chrome/browser/ui/webui/history_ui.cc
index 1d5c83c..50f80f8 100644
--- a/chrome/browser/ui/webui/history_ui.cc
+++ b/chrome/browser/ui/webui/history_ui.cc
@@ -195,7 +195,7 @@ content::WebUIDataSource* CreateHistoryUIHTMLSource(Profile* profile) {
 // indicator (e.g. today, yesterday).
 string16 getRelativeDateLocalized(const base::Time& visit_time) {
   base::Time midnight = base::Time::Now().LocalMidnight();
-  string16 date_str = ui::TimeFormat::RelativeDate(visit_time, &midnight);
+  base::string16 date_str = ui::TimeFormat::RelativeDate(visit_time, &midnight);
   if (date_str.empty()) {
     date_str = base::TimeFormatFriendlyDate(visit_time);
   } else {
@@ -263,9 +263,9 @@ void GetDeviceNameAndType(const ProfileSyncService* sync_service,
 
 BrowsingHistoryHandler::HistoryEntry::HistoryEntry(
     BrowsingHistoryHandler::HistoryEntry::EntryType entry_type,
-    const GURL& url, const string16& title, base::Time time,
+    const GURL& url, const base::string16& title, base::Time time,
     const std::string& client_id, bool is_search_result,
-    const string16& snippet, bool blocked_visit,
+    const base::string16& snippet, bool blocked_visit,
     const std::string& accept_languages) {
   this->entry_type = entry_type;
   this->url = url;
@@ -291,7 +291,7 @@ void BrowsingHistoryHandler::HistoryEntry::SetUrlAndTitle(
   result->SetString("url", url.spec());
 
   bool using_url_as_the_title = false;
-  string16 title_to_set(title);
+  base::string16 title_to_set(title);
   if (title.empty()) {
     using_url_as_the_title = true;
     title_to_set = UTF8ToUTF16(url.spec());
@@ -338,7 +338,7 @@ scoped_ptr<DictionaryValue> BrowsingHistoryHandler::HistoryEntry::ToValue(
     result->SetString("snippet", snippet);
   } else {
     base::Time midnight = base::Time::Now().LocalMidnight();
-    string16 date_str = ui::TimeFormat::RelativeDate(time, &midnight);
+    base::string16 date_str = ui::TimeFormat::RelativeDate(time, &midnight);
     if (date_str.empty()) {
       date_str = base::TimeFormatFriendlyDate(time);
     } else {
@@ -434,7 +434,7 @@ void BrowsingHistoryHandler::WebHistoryTimeout() {
 }
 
 void BrowsingHistoryHandler::QueryHistory(
-    string16 search_text, const history::QueryOptions& options) {
+    base::string16 search_text, const history::QueryOptions& options) {
   Profile* profile = Profile::FromWebUI(web_ui());
 
   // Anything in-flight is invalid.
@@ -486,7 +486,7 @@ void BrowsingHistoryHandler::HandleQueryHistory(const ListValue* args) {
   //   returned.
   // - the maximum number of results to return (may be 0, meaning that there
   //   is no maximum).
-  string16 search_text = ExtractStringValue(args);
+  base::string16 search_text = ExtractStringValue(args);
   int offset;
   if (!args->GetInteger(1, &offset)) {
     NOTREACHED() << "Failed to convert argument 1. ";
@@ -540,7 +540,7 @@ void BrowsingHistoryHandler::HandleRemoveVisits(const ListValue* args) {
   DCHECK(urls_to_be_deleted_.empty());
   for (ListValue::const_iterator it = args->begin(); it != args->end(); ++it) {
     DictionaryValue* deletion = NULL;
-    string16 url;
+    base::string16 url;
     ListValue* timestamps = NULL;
 
     // Each argument is a dictionary with properties "url" and "timestamps".
@@ -641,7 +641,7 @@ void BrowsingHistoryHandler::HandleClearBrowsingData(const ListValue* args) {
 }
 
 void BrowsingHistoryHandler::HandleRemoveBookmark(const ListValue* args) {
-  string16 url = ExtractStringValue(args);
+  base::string16 url = ExtractStringValue(args);
   Profile* profile = Profile::FromWebUI(web_ui());
   BookmarkModel* model = BookmarkModelFactory::GetForProfile(profile);
   bookmark_utils::RemoveAllBookmarks(model, GURL(url));
@@ -741,7 +741,7 @@ void BrowsingHistoryHandler::ReturnResultsToFrontEnd() {
 }
 
 void BrowsingHistoryHandler::QueryComplete(
-    const string16& search_text,
+    const base::string16& search_text,
     const history::QueryOptions& options,
     HistoryService::Handle request_handle,
     history::QueryResults* results) {
@@ -785,7 +785,7 @@ void BrowsingHistoryHandler::QueryComplete(
 }
 
 void BrowsingHistoryHandler::WebHistoryQueryComplete(
-    const string16& search_text,
+    const base::string16& search_text,
     const history::QueryOptions& options,
     base::TimeTicks start_time,
     history::WebHistoryService::Request* request,
@@ -814,8 +814,8 @@ void BrowsingHistoryHandler::WebHistoryQueryComplete(
       const DictionaryValue* result = NULL;
       const ListValue* results = NULL;
       const ListValue* ids = NULL;
-      string16 url;
-      string16 title;
+      base::string16 url;
+      base::string16 title;
       base::Time visit_time;
 
       if (!(events->GetDictionary(i, &event) &&
@@ -859,7 +859,7 @@ void BrowsingHistoryHandler::WebHistoryQueryComplete(
                 time,
                 client_id,
                 !search_text.empty(),
-                string16(),
+                base::string16(),
                 /* blocked_visit */ false,
                 accept_languages));
       }
@@ -993,7 +993,7 @@ HistoryUI::HistoryUI(content::WebUI* web_ui) : WebUIController(web_ui) {
 }
 
 // static
-const GURL HistoryUI::GetHistoryURLWithSearchText(const string16& text) {
+const GURL HistoryUI::GetHistoryURLWithSearchText(const base::string16& text) {
   return GURL(std::string(chrome::kChromeUIHistoryURL) + "#q=" +
               net::EscapeQueryParamValue(UTF16ToUTF8(text), true));
 }
diff --git a/chrome/browser/ui/webui/history_ui.h b/chrome/browser/ui/webui/history_ui.h
index 6c4177a..fc76fef 100644
--- a/chrome/browser/ui/webui/history_ui.h
+++ b/chrome/browser/ui/webui/history_ui.h
@@ -39,9 +39,9 @@ class BrowsingHistoryHandler : public content::WebUIMessageHandler,
       COMBINED_ENTRY
     };
 
-    HistoryEntry(EntryType type, const GURL& url, const string16& title,
+    HistoryEntry(EntryType type, const GURL& url, const base::string16& title,
                  base::Time time, const std::string& client_id,
-                 bool is_search_result, const string16& snippet,
+                 bool is_search_result, const base::string16& snippet,
                  bool blocked_visit, const std::string& accept_languages);
     HistoryEntry();
     virtual ~HistoryEntry();
@@ -63,7 +63,7 @@ class BrowsingHistoryHandler : public content::WebUIMessageHandler,
     EntryType entry_type;
 
     GURL url;
-    string16 title;  // Title of the entry. May be empty.
+    base::string16 title;  // Title of the entry. May be empty.
 
     // The time of the entry. Usually this will be the time of the most recent
     // visit to |url| on a particular day as defined in the local timezone.
@@ -79,7 +79,7 @@ class BrowsingHistoryHandler : public content::WebUIMessageHandler,
     bool is_search_result;
 
     // The entry's search snippet, if this entry is a search result.
-    string16 snippet;
+    base::string16 snippet;
 
     // Whether this entry was blocked when it was attempted.
     bool blocked_visit;
@@ -140,13 +140,13 @@ class BrowsingHistoryHandler : public content::WebUIMessageHandler,
   void WebHistoryTimeout();
 
   // Callback from the history system when a history query has completed.
-  void QueryComplete(const string16& search_text,
+  void QueryComplete(const base::string16& search_text,
                      const history::QueryOptions& options,
                      HistoryService::Handle request_handle,
                      history::QueryResults* results);
 
   // Callback from the WebHistoryService when a query has completed.
-  void WebHistoryQueryComplete(const string16& search_text,
+  void WebHistoryQueryComplete(const base::string16& search_text,
                                const history::QueryOptions& options,
                                base::TimeTicks start_time,
                                history::WebHistoryService::Request* request,
@@ -210,7 +210,7 @@ class HistoryUI : public content::WebUIController {
   explicit HistoryUI(content::WebUI* web_ui);
 
   // Return the URL for a given search term.
-  static const GURL GetHistoryURLWithSearchText(const string16& text);
+  static const GURL GetHistoryURLWithSearchText(const base::string16& text);
 
   static base::RefCountedMemory* GetFaviconResourceBytes(
       ui::ScaleFactor scale_factor);
diff --git a/chrome/browser/ui/webui/inline_login_ui.cc b/chrome/browser/ui/webui/inline_login_ui.cc
index 7652990..1b3822c 100644
--- a/chrome/browser/ui/webui/inline_login_ui.cc
+++ b/chrome/browser/ui/webui/inline_login_ui.cc
@@ -205,7 +205,7 @@ class InlineLoginUIHandler : public content::WebUIMessageHandler {
 
   // JS callback:
   void HandleSwitchToFullTab(const base::ListValue* args) {
-    string16 url_str;
+    base::string16 url_str;
     CHECK(args->GetString(0, &url_str));
 
     content::WebContents* web_contents = web_ui()->GetWebContents();
@@ -233,8 +233,8 @@ class InlineLoginUIHandler : public content::WebUIMessageHandler {
     oauth2_token_fetcher_->StartExchangeFromCookies();
 #else
     const base::DictionaryValue* dict = NULL;
-    string16 email;
-    string16 password;
+    base::string16 email;
+    base::string16 password;
     if (!args->GetDictionary(0, &dict) || !dict ||
         !dict->GetString("email", &email)) {
       NOTREACHED();
@@ -281,8 +281,8 @@ class InlineLoginUIHandler : public content::WebUIMessageHandler {
   }
 
   void OnGaiaCookiesFetched(
-      const string16 email,
-      const string16 password,
+      const base::string16 email,
+      const base::string16 password,
       const net::CookieList& cookie_list) {
     net::CookieList::const_iterator it;
     std::string oauth_code;
diff --git a/chrome/browser/ui/webui/local_discovery/local_discovery_ui_handler.cc b/chrome/browser/ui/webui/local_discovery/local_discovery_ui_handler.cc
index 21421df..cddc71b 100644
--- a/chrome/browser/ui/webui/local_discovery/local_discovery_ui_handler.cc
+++ b/chrome/browser/ui/webui/local_discovery/local_discovery_ui_handler.cc
@@ -597,7 +597,7 @@ void LocalDiscoveryUIHandler::SetupCloudPrintConnectorSection() {
   }
   base::FundamentalValue disabled(email.empty());
 
-  string16 label_str;
+  base::string16 label_str;
   if (email.empty()) {
     label_str = l10n_util::GetStringFUTF16(
         IDS_LOCAL_DISCOVERY_CLOUD_PRINT_CONNECTOR_DISABLED_LABEL,
diff --git a/chrome/browser/ui/webui/memory_internals/memory_internals_handler.cc b/chrome/browser/ui/webui/memory_internals/memory_internals_handler.cc
index 1cba471..00e0863 100644
--- a/chrome/browser/ui/webui/memory_internals/memory_internals_handler.cc
+++ b/chrome/browser/ui/webui/memory_internals/memory_internals_handler.cc
@@ -38,7 +38,7 @@ void MemoryInternalsHandler::OnJSUpdate(const base::ListValue* list) {
   proxy_->StartFetch(list);
 }
 
-void MemoryInternalsHandler::OnUpdate(const string16& update) {
+void MemoryInternalsHandler::OnUpdate(const base::string16& update) {
   // Don't try to execute JavaScript in a RenderView that no longer exists.
   content::RenderViewHost* host =
       web_ui()->GetWebContents()->GetRenderViewHost();
diff --git a/chrome/browser/ui/webui/memory_internals/memory_internals_handler.h b/chrome/browser/ui/webui/memory_internals/memory_internals_handler.h
index 8cc9ce0..78ba377 100644
--- a/chrome/browser/ui/webui/memory_internals/memory_internals_handler.h
+++ b/chrome/browser/ui/webui/memory_internals/memory_internals_handler.h
@@ -30,7 +30,7 @@ class MemoryInternalsHandler : public content::WebUIMessageHandler {
   void OnJSUpdate(const base::ListValue* list);
 
   // MemoryInternals message handlers.
-  void OnUpdate(const string16& update);
+  void OnUpdate(const base::string16& update);
 
  private:
   scoped_refptr<MemoryInternalsProxy> proxy_;
diff --git a/chrome/browser/ui/webui/memory_internals/memory_internals_proxy.cc b/chrome/browser/ui/webui/memory_internals/memory_internals_proxy.cc
index 2e549f0..4c465ee 100644
--- a/chrome/browser/ui/webui/memory_internals/memory_internals_proxy.cc
+++ b/chrome/browser/ui/webui/memory_internals/memory_internals_proxy.cc
@@ -353,7 +353,8 @@ void MemoryInternalsProxy::CallJavaScriptFunctionOnUIThread(
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   std::vector<const base::Value*> args_vector(1, &args);
-  string16 update = content::WebUI::GetJavascriptCall(function, args_vector);
+  base::string16 update =
+      content::WebUI::GetJavascriptCall(function, args_vector);
   // Don't forward updates to a destructed UI.
   if (handler_)
     handler_->OnUpdate(update);
diff --git a/chrome/browser/ui/webui/nacl_ui.cc b/chrome/browser/ui/webui/nacl_ui.cc
index de7e26e..7408325 100644
--- a/chrome/browser/ui/webui/nacl_ui.cc
+++ b/chrome/browser/ui/webui/nacl_ui.cc
@@ -154,7 +154,9 @@ void NaClDomHandler::RegisterMessages() {
 
 // Helper functions for collecting a list of key-value pairs that will
 // be displayed.
-void AddPair(ListValue* list, const string16& key, const string16& value) {
+void AddPair(ListValue* list,
+             const base::string16& key,
+             const base::string16& value) {
   DictionaryValue* results = new DictionaryValue();
   results->SetString("key", key);
   results->SetString("value", value);
@@ -217,8 +219,8 @@ void NaClDomHandler::AddPluginList(ListValue* list) {
   std::vector<content::WebPluginInfo> info_array;
   PluginService::GetInstance()->GetPluginInfoArray(
       GURL(), "application/x-nacl", false, &info_array, NULL);
-  string16 nacl_version;
-  string16 nacl_key = ASCIIToUTF16("NaCl plugin");
+  base::string16 nacl_version;
+  base::string16 nacl_key = ASCIIToUTF16("NaCl plugin");
   if (info_array.empty()) {
     AddPair(list, nacl_key, ASCIIToUTF16("Disabled"));
   } else {
@@ -247,7 +249,7 @@ void NaClDomHandler::AddPluginList(ListValue* list) {
 
 void NaClDomHandler::AddPnaclInfo(ListValue* list) {
   // Display whether PNaCl is enabled.
-  string16 pnacl_enabled_string = ASCIIToUTF16("Enabled");
+  base::string16 pnacl_enabled_string = ASCIIToUTF16("Enabled");
   if (!isPluginEnabled(0)) {
     pnacl_enabled_string = ASCIIToUTF16("Disabled in profile prefs");
   } else if (CommandLine::ForCurrentProcess()->HasSwitch(
@@ -277,7 +279,7 @@ void NaClDomHandler::AddPnaclInfo(ListValue* list) {
 }
 
 void NaClDomHandler::AddNaClInfo(ListValue* list) {
-  string16 nacl_enabled_string = ASCIIToUTF16("Disabled");
+  base::string16 nacl_enabled_string = ASCIIToUTF16("Disabled");
   if (isPluginEnabled(0) &&
       CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnableNaCl)) {
     nacl_enabled_string = ASCIIToUTF16("Enabled by flag '--enable-nacl'");
diff --git a/chrome/browser/ui/webui/net_internals/net_internals_ui.cc b/chrome/browser/ui/webui/net_internals/net_internals_ui.cc
index 2f40b4d..fdceb4e 100644
--- a/chrome/browser/ui/webui/net_internals/net_internals_ui.cc
+++ b/chrome/browser/ui/webui/net_internals/net_internals_ui.cc
@@ -1187,7 +1187,7 @@ void NetInternalsMessageHandler::IOThreadImpl::OnEnableIPv6(
 void NetInternalsMessageHandler::IOThreadImpl::OnStartConnectionTests(
     const ListValue* list) {
   // |value| should be: [<URL to test>].
-  string16 url_str;
+  base::string16 url_str;
   CHECK(list->GetString(0, &url_str));
 
   // Try to fix-up the user provided URL into something valid.
diff --git a/chrome/browser/ui/webui/ntp/android/context_menu_handler.cc b/chrome/browser/ui/webui/ntp/android/context_menu_handler.cc
index 7c916f4..328be22 100644
--- a/chrome/browser/ui/webui/ntp/android/context_menu_handler.cc
+++ b/chrome/browser/ui/webui/ntp/android/context_menu_handler.cc
@@ -126,7 +126,7 @@ void ContextMenuHandler::HandleOpenInIncognitoTab(const ListValue* args) {
 
 void ContextMenuHandler::OpenUrl(const ListValue* args,
                                  WindowOpenDisposition disposition) {
-  string16 url = ExtractStringValue(args);
+  base::string16 url = ExtractStringValue(args);
   if (!url.empty()) {
     web_ui()->GetWebContents()->OpenURL(content::OpenURLParams(
         GURL(url), content::Referrer(), disposition,
diff --git a/chrome/browser/ui/webui/ntp/android/ntp_resource_cache_android.cc b/chrome/browser/ui/webui/ntp/android/ntp_resource_cache_android.cc
index 29b8cd8..0b09b2d 100644
--- a/chrome/browser/ui/webui/ntp/android/ntp_resource_cache_android.cc
+++ b/chrome/browser/ui/webui/ntp/android/ntp_resource_cache_android.cc
@@ -149,7 +149,7 @@ void NTPResourceCache::CreateNewTabHTML() {
       bookmark_shortcuts_allowed ? "true" : "false");
 
   const char* new_tab_link = kLearnMoreIncognitoUrl;
-  string16 learnMoreLink = ASCIIToUTF16(
+  base::string16 learnMoreLink = ASCIIToUTF16(
       google_util::AppendGoogleLocaleParam(GURL(new_tab_link)).spec());
   localized_strings.SetString("content",
       l10n_util::GetStringFUTF16(
diff --git a/chrome/browser/ui/webui/ntp/android/promo_handler.cc b/chrome/browser/ui/webui/ntp/android/promo_handler.cc
index b3a1663..fc43d70 100644
--- a/chrome/browser/ui/webui/ntp/android/promo_handler.cc
+++ b/chrome/browser/ui/webui/ntp/android/promo_handler.cc
@@ -152,7 +152,7 @@ void PromoHandler::HandlePromoSendEmail(const base::ListValue* args) {
   if (!profile)
     return;
 
-  string16 data_subject, data_body, data_inv;
+  base::string16 data_subject, data_body, data_inv;
   if (!args || args->GetSize() < 3) {
     DVLOG(1) << "promoSendEmail: expected three args, got "
              << (args ? args->GetSize() : 0);
diff --git a/chrome/browser/ui/webui/ntp/app_launcher_handler.cc b/chrome/browser/ui/webui/ntp/app_launcher_handler.cc
index 0d6383a..e35efca 100644
--- a/chrome/browser/ui/webui/ntp/app_launcher_handler.cc
+++ b/chrome/browser/ui/webui/ntp/app_launcher_handler.cc
@@ -114,14 +114,14 @@ void AppLauncherHandler::CreateAppInfo(
 
   // The Extension class 'helpfully' wraps bidi control characters that
   // impede our ability to determine directionality.
-  string16 short_name = UTF8ToUTF16(extension->short_name());
+  base::string16 short_name = UTF8ToUTF16(extension->short_name());
   base::i18n::UnadjustStringForLocaleDirection(&short_name);
   NewTabUI::SetUrlTitleAndDirection(
       value,
       short_name,
       extensions::AppLaunchInfo::GetFullLaunchURL(extension));
 
-  string16 name = UTF8ToUTF16(extension->name());
+  base::string16 name = UTF8ToUTF16(extension->name());
   base::i18n::UnadjustStringForLocaleDirection(&name);
   NewTabUI::SetFullNameAndDirection(name, value);
 
@@ -657,7 +657,7 @@ void AppLauncherHandler::HandleSetPageIndex(const ListValue* args) {
 }
 
 void AppLauncherHandler::HandleSaveAppPageName(const ListValue* args) {
-  string16 name;
+  base::string16 name;
   CHECK(args->GetString(0, &name));
 
   double page_index;
@@ -675,7 +675,7 @@ void AppLauncherHandler::HandleGenerateAppForLink(const ListValue* args) {
   CHECK(args->GetString(0, &url));
   GURL launch_url(url);
 
-  string16 title;
+  base::string16 title;
   CHECK(args->GetString(1, &title));
 
   double page_index;
diff --git a/chrome/browser/ui/webui/ntp/app_launcher_handler.h b/chrome/browser/ui/webui/ntp/app_launcher_handler.h
index 411779a..a3547bb 100644
--- a/chrome/browser/ui/webui/ntp/app_launcher_handler.h
+++ b/chrome/browser/ui/webui/ntp/app_launcher_handler.h
@@ -112,7 +112,7 @@ class AppLauncherHandler : public content::WebUIMessageHandler,
     ~AppInstallInfo();
 
     bool is_bookmark_app;
-    string16 title;
+    base::string16 title;
     GURL app_url;
     syncer::StringOrdinal page_ordinal;
   };
diff --git a/chrome/browser/ui/webui/ntp/foreign_session_handler.h b/chrome/browser/ui/webui/ntp/foreign_session_handler.h
index 443f124..477061a 100644
--- a/chrome/browser/ui/webui/ntp/foreign_session_handler.h
+++ b/chrome/browser/ui/webui/ntp/foreign_session_handler.h
@@ -65,7 +65,7 @@ class ForeignSessionHandler : public content::WebUIMessageHandler,
   bool IsTabSyncEnabled();
 
   // Returns a string used to show the user when a session was last modified.
-  string16 FormatSessionTime(const base::Time& time);
+  base::string16 FormatSessionTime(const base::Time& time);
 
   // Determines which session is to be opened, and then calls
   // OpenForeignSession, to begin the process of opening a new browser window.
diff --git a/chrome/browser/ui/webui/ntp/new_tab_page_sync_handler.cc b/chrome/browser/ui/webui/ntp/new_tab_page_sync_handler.cc
index 74ab381..53dad5c 100644
--- a/chrome/browser/ui/webui/ntp/new_tab_page_sync_handler.cc
+++ b/chrome/browser/ui/webui/ntp/new_tab_page_sync_handler.cc
@@ -111,8 +111,8 @@ void NewTabPageSyncHandler::BuildAndSendSyncStatus() {
   // "Sync error", when we can't authenticate or establish a connection with
   //               the sync server (appropriate information appended to
   //               message).
-  string16 status_msg;
-  string16 link_text;
+  base::string16 status_msg;
+  base::string16 link_text;
 
   sync_ui_util::MessageType type =
       sync_ui_util::GetStatusLabelsForNewTabPage(sync_service_,
@@ -134,7 +134,7 @@ void NewTabPageSyncHandler::HandleSyncLinkClicked(const ListValue* args) {
   chrome::ShowBrowserSignin(browser, signin::SOURCE_NTP_LINK);
 
   if (sync_service_->HasSyncSetupCompleted()) {
-    string16 user = UTF8ToUTF16(SigninManagerFactory::GetForProfile(
+    base::string16 user = UTF8ToUTF16(SigninManagerFactory::GetForProfile(
         Profile::FromWebUI(web_ui()))->GetAuthenticatedUsername());
     DictionaryValue value;
     value.SetString("syncEnabledMessage",
diff --git a/chrome/browser/ui/webui/ntp/new_tab_ui.cc b/chrome/browser/ui/webui/ntp/new_tab_ui.cc
index 8d04ea5..36c9cd2 100644
--- a/chrome/browser/ui/webui/ntp/new_tab_ui.cc
+++ b/chrome/browser/ui/webui/ntp/new_tab_ui.cc
@@ -76,7 +76,7 @@ const char kLTRHtmlTextDirection[] = "ltr";
 
 static base::LazyInstance<std::set<const WebUIController*> > g_live_new_tabs;
 
-const char* GetHtmlTextDirection(const string16& text) {
+const char* GetHtmlTextDirection(const base::string16& text) {
   if (base::i18n::IsRTL() && base::i18n::StringContainsStrongRTLChars(text))
     return kRTLHtmlTextDirection;
   else
@@ -294,12 +294,12 @@ bool NewTabUI::IsDiscoveryInNTPEnabled() {
 
 // static
 void NewTabUI::SetUrlTitleAndDirection(DictionaryValue* dictionary,
-                                       const string16& title,
+                                       const base::string16& title,
                                        const GURL& gurl) {
   dictionary->SetString("url", gurl.spec());
 
   bool using_url_as_the_title = false;
-  string16 title_to_set(title);
+  base::string16 title_to_set(title);
   if (title_to_set.empty()) {
     using_url_as_the_title = true;
     title_to_set = UTF8ToUTF16(gurl.spec());
@@ -327,7 +327,7 @@ void NewTabUI::SetUrlTitleAndDirection(DictionaryValue* dictionary,
 }
 
 // static
-void NewTabUI::SetFullNameAndDirection(const string16& full_name,
+void NewTabUI::SetFullNameAndDirection(const base::string16& full_name,
                                        base::DictionaryValue* dictionary) {
   dictionary->SetString("full_name", full_name);
   dictionary->SetString("full_name_direction", GetHtmlTextDirection(full_name));
diff --git a/chrome/browser/ui/webui/ntp/new_tab_ui.h b/chrome/browser/ui/webui/ntp/new_tab_ui.h
index 490085a2..b28775a 100644
--- a/chrome/browser/ui/webui/ntp/new_tab_ui.h
+++ b/chrome/browser/ui/webui/ntp/new_tab_ui.h
@@ -56,11 +56,11 @@ class NewTabUI : public content::WebUIController,
   // Adds "url", "title", and "direction" keys on incoming dictionary, setting
   // title as the url as a fallback on empty title.
   static void SetUrlTitleAndDirection(base::DictionaryValue* dictionary,
-                                      const string16& title,
+                                      const base::string16& title,
                                       const GURL& gurl);
 
   // Adds "full_name" and "full_name_direction" keys on incoming dictionary.
-  static void SetFullNameAndDirection(const string16& full_name,
+  static void SetFullNameAndDirection(const base::string16& full_name,
                                       base::DictionaryValue* dictionary);
 
   // Returns a pointer to a NewTabUI if the WebUIController object is a new tab
diff --git a/chrome/browser/ui/webui/ntp/ntp_login_handler.cc b/chrome/browser/ui/webui/ntp/ntp_login_handler.cc
index 35a31b0..0185258 100644
--- a/chrome/browser/ui/webui/ntp/ntp_login_handler.cc
+++ b/chrome/browser/ui/webui/ntp/ntp_login_handler.cc
@@ -69,7 +69,7 @@ SkBitmap GetGAIAPictureForNTP(const gfx::Image& image) {
 }
 
 // Puts the |content| into a span with the given CSS class.
-string16 CreateSpanWithClass(const string16& content,
+string16 CreateSpanWithClass(const base::string16& content,
                              const std::string& css_class) {
   return ASCIIToUTF16("<span class='" + css_class + "'>") +
       net::EscapeForHTML(content) + ASCIIToUTF16("</span>");
@@ -201,7 +201,7 @@ void NTPLoginHandler::UpdateLogin() {
   std::string username = profile->GetPrefs()->GetString(
       prefs::kGoogleServicesUsername);
 
-  string16 header, sub_header;
+  base::string16 header, sub_header;
   std::string icon_url;
   if (!username.empty()) {
     ProfileInfoCache& cache =
@@ -212,7 +212,7 @@ void NTPLoginHandler::UpdateLogin() {
       // case. In the multi-profile case the profile picture is visible in the
       // title bar and the full name can be ambiguous.
       if (cache.GetNumberOfProfiles() == 1) {
-        string16 name = cache.GetGAIANameOfProfileAtIndex(profile_index);
+        base::string16 name = cache.GetGAIANameOfProfileAtIndex(profile_index);
         if (!name.empty())
           header = CreateSpanWithClass(name, "profile-name");
         const gfx::Image* image =
@@ -233,7 +233,7 @@ void NTPLoginHandler::UpdateLogin() {
     SigninManager* signin = SigninManagerFactory::GetForProfile(
         profile->GetOriginalProfile());
     if (!profile->IsManaged() && signin->IsSigninAllowed()) {
-      string16 signed_in_link = l10n_util::GetStringUTF16(
+      base::string16 signed_in_link = l10n_util::GetStringUTF16(
           IDS_SYNC_PROMO_NOT_SIGNED_IN_STATUS_LINK);
       signed_in_link = CreateSpanWithClass(signed_in_link, "link-span");
       header = l10n_util::GetStringFUTF16(
@@ -273,7 +273,7 @@ void NTPLoginHandler::GetLocalizedValues(Profile* profile,
   PrefService* prefs = profile->GetPrefs();
   bool hide_sync = !prefs->GetBoolean(prefs::kSignInPromoShowNTPBubble);
 
-  string16 message = hide_sync ? string16() :
+  base::string16 message = hide_sync ? base::string16() :
       l10n_util::GetStringFUTF16(IDS_SYNC_PROMO_NTP_BUBBLE_MESSAGE,
           l10n_util::GetStringUTF16(IDS_SHORT_PRODUCT_NAME));
 
@@ -281,9 +281,9 @@ void NTPLoginHandler::GetLocalizedValues(Profile* profile,
   values->SetString("login_status_url",
       hide_sync ? std::string() : chrome::kSyncLearnMoreURL);
   values->SetString("login_status_advanced",
-      hide_sync ? string16() :
+      hide_sync ? base::string16() :
       l10n_util::GetStringUTF16(IDS_SYNC_PROMO_NTP_BUBBLE_ADVANCED));
   values->SetString("login_status_dismiss",
-      hide_sync ? string16() :
+      hide_sync ? base::string16() :
       l10n_util::GetStringUTF16(IDS_SYNC_PROMO_NTP_BUBBLE_OK));
 }
diff --git a/chrome/browser/ui/webui/ntp/ntp_resource_cache.cc b/chrome/browser/ui/webui/ntp/ntp_resource_cache.cc
index a62fe18..73a05ed 100644
--- a/chrome/browser/ui/webui/ntp/ntp_resource_cache.cc
+++ b/chrome/browser/ui/webui/ntp/ntp_resource_cache.cc
@@ -309,7 +309,7 @@ void NTPResourceCache::CreateNewTabIncognitoHTML() {
     if (!enterprise_domain.empty()) {
       // Device is enterprise enrolled.
       localized_strings.SetString("enterpriseInfoVisible", "true");
-      string16 enterprise_info = l10n_util::GetStringFUTF16(
+      base::string16 enterprise_info = l10n_util::GetStringFUTF16(
           IDS_DEVICE_OWNED_BY_NOTICE,
           UTF8ToUTF16(enterprise_domain));
       localized_strings.SetString("enterpriseInfoMessage", enterprise_info);
diff --git a/chrome/browser/ui/webui/ntp/ntp_resource_cache.h b/chrome/browser/ui/webui/ntp/ntp_resource_cache.h
index a5203e1..cc76dd2 100644
--- a/chrome/browser/ui/webui/ntp/ntp_resource_cache.h
+++ b/chrome/browser/ui/webui/ntp/ntp_resource_cache.h
@@ -79,7 +79,7 @@ class NTPResourceCache : public content::NotificationObserver,
 #if !defined(OS_ANDROID)
   // Returns a message describing any newly-added sync types, or an empty
   // string if all types have already been acknowledged.
-  string16 GetSyncTypeMessage();
+  base::string16 GetSyncTypeMessage();
 
   void CreateNewTabIncognitoHTML();
   void CreateNewTabIncognitoCSS();
diff --git a/chrome/browser/ui/webui/omnibox/omnibox_ui_handler.cc b/chrome/browser/ui/webui/omnibox/omnibox_ui_handler.cc
index ac24b5b..6e35ec3 100644
--- a/chrome/browser/ui/webui/omnibox/omnibox_ui_handler.cc
+++ b/chrome/browser/ui/webui/omnibox/omnibox_ui_handler.cc
@@ -80,7 +80,7 @@ void OmniboxUIHandler::OnResultChanged(bool default_match_changed) {
   result_to_output.SetBoolean("done", controller_->done());
   result_to_output.SetInteger("time_since_omnibox_started_ms",
       (base::Time::Now() - time_omnibox_started_).InMilliseconds());
-  const string16& host = controller_->input().text().substr(
+  const base::string16& host = controller_->input().text().substr(
       controller_->input().parts().host.begin,
       controller_->input().parts().host.len);
   result_to_output.SetString("host", host);
@@ -158,7 +158,7 @@ void OmniboxUIHandler::AddResultToDictionary(const std::string& prefix,
   output->SetInteger(prefix + ".num_items", i);
 }
 
-bool OmniboxUIHandler::LookupIsTypedHost(const string16& host,
+bool OmniboxUIHandler::LookupIsTypedHost(const base::string16& host,
                                          bool* is_typed_host) const {
   HistoryService* const history_service =
       HistoryServiceFactory::GetForProfile(profile_,
@@ -174,7 +174,7 @@ bool OmniboxUIHandler::LookupIsTypedHost(const string16& host,
 
 void OmniboxUIHandler::StartOmniboxQuery(const base::ListValue* input) {
   DCHECK_EQ(4u, input->GetSize());
-  string16 input_string;
+  base::string16 input_string;
   bool return_val = input->GetString(0, &input_string);
   DCHECK(return_val);
   int cursor_position;
@@ -196,7 +196,7 @@ void OmniboxUIHandler::StartOmniboxQuery(const base::ListValue* input) {
   controller_->Start(AutocompleteInput(
       input_string,
       cursor_position,
-      string16(),  // user's desired tld (top-level domain)
+      base::string16(),  // user's desired tld (top-level domain)
       GURL(),
       AutocompleteInput::INVALID_SPEC,
       prevent_inline_autocomplete,
diff --git a/chrome/browser/ui/webui/omnibox/omnibox_ui_handler.h b/chrome/browser/ui/webui/omnibox/omnibox_ui_handler.h
index 8c18792..f19cbb4 100644
--- a/chrome/browser/ui/webui/omnibox/omnibox_ui_handler.h
+++ b/chrome/browser/ui/webui/omnibox/omnibox_ui_handler.h
@@ -68,7 +68,7 @@ class OmniboxUIHandler : public AutocompleteControllerDelegate,
   // Looks up whether the hostname is a typed host (i.e., has received
   // typed visits).  Return true if the lookup succeeded; if so, the
   // value of |is_typed_host| is set appropriately.
-  bool LookupIsTypedHost(const string16& host, bool* is_typed_host) const;
+  bool LookupIsTypedHost(const base::string16& host, bool* is_typed_host) const;
 
   // Re-initializes the AutocompleteController in preparation for the
   // next query.
diff --git a/chrome/browser/ui/webui/options/autofill_options_handler.cc b/chrome/browser/ui/webui/options/autofill_options_handler.cc
index 3e52253..defae47 100644
--- a/chrome/browser/ui/webui/options/autofill_options_handler.cc
+++ b/chrome/browser/ui/webui/options/autofill_options_handler.cc
@@ -98,7 +98,7 @@ void SetValueList(const ListValue* list,
                   AutofillProfile* profile) {
   std::vector<string16> values(list->GetSize());
   for (size_t i = 0; i < list->GetSize(); ++i) {
-    string16 value;
+    base::string16 value;
     if (list->GetString(i, &value))
       values[i] = value;
   }
@@ -146,17 +146,17 @@ void SetNameList(const ListValue* names, AutofillProfile* profile) {
     bool success = names->GetList(i, &name);
     DCHECK(success);
 
-    string16 first_name;
+    base::string16 first_name;
     success = name->GetString(0, &first_name);
     DCHECK(success);
     first_names[i] = first_name;
 
-    string16 middle_name;
+    base::string16 middle_name;
     success = name->GetString(1, &middle_name);
     DCHECK(success);
     middle_names[i] = middle_name;
 
-    string16 last_name;
+    base::string16 last_name;
     success = name->GetString(2, &last_name);
     DCHECK(success);
     last_names[i] = last_name;
@@ -200,7 +200,7 @@ void ExtractPhoneNumberInformation(const ListValue* args,
 void RemoveDuplicatePhoneNumberAtIndex(size_t index,
                                        const std::string& country_code,
                                        ListValue* list) {
-  string16 new_value;
+  base::string16 new_value;
   if (!list->GetString(index, &new_value)) {
     NOTREACHED() << "List should have a value at index " << index;
     return;
@@ -212,7 +212,7 @@ void RemoveDuplicatePhoneNumberAtIndex(size_t index,
     if (i == index)
       continue;
 
-    string16 existing_value;
+    base::string16 existing_value;
     if (!list->GetString(i, &existing_value)) {
       NOTREACHED() << "List should have a value at index " << i;
       continue;
@@ -520,7 +520,7 @@ void AutofillOptionsHandler::SetAddress(const ListValue* args) {
   AutofillProfile profile(guid, kSettingsOrigin);
 
   std::string country_code;
-  string16 value;
+  base::string16 value;
   const ListValue* list_value;
   if (args->GetList(1, &list_value))
     SetNameList(list_value, &profile);
@@ -573,7 +573,7 @@ void AutofillOptionsHandler::SetCreditCard(const ListValue* args) {
 
   CreditCard credit_card(guid, kSettingsOrigin);
 
-  string16 value;
+  base::string16 value;
   if (args->GetString(1, &value))
     credit_card.SetRawInfo(autofill::CREDIT_CARD_NAME, value);
 
diff --git a/chrome/browser/ui/webui/options/browser_options_handler.cc b/chrome/browser/ui/webui/options/browser_options_handler.cc
index b21e156..81d2fb48 100644
--- a/chrome/browser/ui/webui/options/browser_options_handler.cc
+++ b/chrome/browser/ui/webui/options/browser_options_handler.cc
@@ -470,7 +470,7 @@ void BrowserOptionsHandler::GetLocalizedValues(DictionaryValue* values) {
 #endif
 
   values->SetString("syncLearnMoreURL", chrome::kSyncLearnMoreURL);
-  string16 omnibox_url = ASCIIToUTF16(chrome::kOmniboxLearnMoreURL);
+  base::string16 omnibox_url = ASCIIToUTF16(chrome::kOmniboxLearnMoreURL);
   values->SetString(
       "defaultSearchGroupLabel",
       l10n_util::GetStringFUTF16(IDS_SEARCH_PREF_EXPLANATION, omnibox_url));
@@ -1242,8 +1242,8 @@ scoped_ptr<DictionaryValue> BrowserOptionsHandler::GetSyncStateDictionary() {
   sync_status->SetBoolean("setupInProgress",
       service && !service->IsManaged() && service->FirstSetupInProgress());
 
-  string16 status_label;
-  string16 link_label;
+  base::string16 status_label;
+  base::string16 link_label;
   bool status_has_error = sync_ui_util::GetStatusLabels(
       service, *signin, sync_ui_util::WITH_HTML, &status_label, &link_label) ==
           sync_ui_util::SYNC_ERROR;
@@ -1457,7 +1457,7 @@ void BrowserOptionsHandler::SetupCloudPrintConnectorSection() {
   }
   base::FundamentalValue disabled(email.empty());
 
-  string16 label_str;
+  base::string16 label_str;
   if (email.empty()) {
     label_str = l10n_util::GetStringFUTF16(
         IDS_OPTIONS_CLOUD_PRINT_CONNECTOR_DISABLED_LABEL,
diff --git a/chrome/browser/ui/webui/options/certificate_manager_handler.cc b/chrome/browser/ui/webui/options/certificate_manager_handler.cc
index df9b3f4..ce94778 100644
--- a/chrome/browser/ui/webui/options/certificate_manager_handler.cc
+++ b/chrome/browser/ui/webui/options/certificate_manager_handler.cc
@@ -85,8 +85,8 @@ struct DictionaryIdComparator {
     DCHECK(b->GetType() == Value::TYPE_DICTIONARY);
     const DictionaryValue* a_dict = reinterpret_cast<const DictionaryValue*>(a);
     const DictionaryValue* b_dict = reinterpret_cast<const DictionaryValue*>(b);
-    string16 a_str;
-    string16 b_str;
+    base::string16 a_str;
+    base::string16 b_str;
     a_dict->GetString(kNameId, &a_str);
     b_dict->GetString(kNameId, &b_str);
     if (collator_ == NULL)
@@ -608,7 +608,7 @@ void CertificateManagerHandler::ExportPersonal(const ListValue* args) {
   select_file_dialog_ = ui::SelectFileDialog::Create(
       this, new ChromeSelectFilePolicy(web_ui()->GetWebContents()));
   select_file_dialog_->SelectFile(
-      ui::SelectFileDialog::SELECT_SAVEAS_FILE, string16(),
+      ui::SelectFileDialog::SELECT_SAVEAS_FILE, base::string16(),
       base::FilePath(), &file_type_info, 1, FILE_PATH_LITERAL("p12"),
       GetParentWindow(),
       reinterpret_cast<void*>(EXPORT_PERSONAL_FILE_SELECTED));
@@ -699,7 +699,7 @@ void CertificateManagerHandler::StartImportPersonal(const ListValue* args) {
   select_file_dialog_ = ui::SelectFileDialog::Create(
       this, new ChromeSelectFilePolicy(web_ui()->GetWebContents()));
   select_file_dialog_->SelectFile(
-      ui::SelectFileDialog::SELECT_OPEN_FILE, string16(),
+      ui::SelectFileDialog::SELECT_OPEN_FILE, base::string16(),
       base::FilePath(), &file_type_info, 1, FILE_PATH_LITERAL("p12"),
       GetParentWindow(),
       reinterpret_cast<void*>(IMPORT_PERSONAL_FILE_SELECTED));
diff --git a/chrome/browser/ui/webui/options/certificate_manager_handler.h b/chrome/browser/ui/webui/options/certificate_manager_handler.h
index 47e42011..0923309 100644
--- a/chrome/browser/ui/webui/options/certificate_manager_handler.h
+++ b/chrome/browser/ui/webui/options/certificate_manager_handler.h
@@ -173,7 +173,7 @@ class CertificateManagerHandler
   // password, etc the user chose while we wait for them to enter a password,
   // wait for file to be read, etc.
   base::FilePath file_path_;
-  string16 password_;
+  base::string16 password_;
   bool use_hardware_backed_;
   std::string file_data_;
   net::CertificateList selected_cert_list_;
diff --git a/chrome/browser/ui/webui/options/chromeos/cros_language_options_handler.cc b/chrome/browser/ui/webui/options/chromeos/cros_language_options_handler.cc
index 23a6a13..0f550a5 100644
--- a/chrome/browser/ui/webui/options/chromeos/cros_language_options_handler.cc
+++ b/chrome/browser/ui/webui/options/chromeos/cros_language_options_handler.cc
@@ -199,7 +199,7 @@ ListValue* CrosLanguageOptionsHandler::GetLanguageListInternal(
   // In theory, we should be able to create a map that is sorted by
   // display names using ICU comparator, but doing it is hard, thus we'll
   // use an auxiliary vector to achieve the same result.
-  typedef std::pair<std::string, string16> LanguagePair;
+  typedef std::pair<std::string, base::string16> LanguagePair;
   typedef std::map<string16, LanguagePair> LanguageMap;
   LanguageMap language_map;
   // The auxiliary vector mentioned above.
@@ -216,9 +216,9 @@ ListValue* CrosLanguageOptionsHandler::GetLanguageListInternal(
       continue;
     }
 
-    const string16 display_name =
+    const base::string16 display_name =
         l10n_util::GetDisplayNameForLocale(*iter, app_locale, true);
-    const string16 native_display_name =
+    const base::string16 native_display_name =
         l10n_util::GetDisplayNameForLocale(*iter, *iter, true);
 
     display_names.push_back(display_name);
@@ -238,10 +238,10 @@ ListValue* CrosLanguageOptionsHandler::GetLanguageListInternal(
     if (IsBlacklisted(base_language_codes[i]))
       continue;
 
-    string16 display_name =
+    base::string16 display_name =
         l10n_util::GetDisplayNameForLocale(
             base_language_codes[i], app_locale, false);
-    string16 native_display_name =
+    base::string16 native_display_name =
         l10n_util::GetDisplayNameForLocale(
             base_language_codes[i], base_language_codes[i], false);
     display_names.push_back(display_name);
@@ -256,7 +256,7 @@ ListValue* CrosLanguageOptionsHandler::GetLanguageListInternal(
   ListValue* language_list = new ListValue();
   for (size_t i = 0; i < display_names.size(); ++i) {
     // Sets the directionality of the display language name.
-    string16 display_name(display_names[i]);
+    base::string16 display_name(display_names[i]);
     bool markup_removal =
         base::i18n::UnadjustStringForLocaleDirection(&display_name);
     DCHECK(markup_removal);
diff --git a/chrome/browser/ui/webui/options/chromeos/cros_language_options_handler.h b/chrome/browser/ui/webui/options/chromeos/cros_language_options_handler.h
index e811f14..32bf026 100644
--- a/chrome/browser/ui/webui/options/chromeos/cros_language_options_handler.h
+++ b/chrome/browser/ui/webui/options/chromeos/cros_language_options_handler.h
@@ -65,7 +65,7 @@ class CrosLanguageOptionsHandler
 
  private:
   // LanguageOptionsHandlerCommon implementation.
-  virtual string16 GetProductName() OVERRIDE;
+  virtual base::string16 GetProductName() OVERRIDE;
   virtual void SetApplicationLocale(const std::string& language_code) OVERRIDE;
 
   // Called when the sign-out button is clicked.
diff --git a/chrome/browser/ui/webui/options/clear_browser_data_handler.cc b/chrome/browser/ui/webui/options/clear_browser_data_handler.cc
index 0b578e0..32ff67e 100644
--- a/chrome/browser/ui/webui/options/clear_browser_data_handler.cc
+++ b/chrome/browser/ui/webui/options/clear_browser_data_handler.cc
@@ -109,7 +109,7 @@ void ClearBrowserDataHandler::GetLocalizedValues(
 
   ListValue* time_list = new ListValue;
   for (int i = 0; i < 5; i++) {
-    string16 label_string;
+    base::string16 label_string;
     switch (i) {
       case 0:
         label_string = l10n_util::GetStringUTF16(IDS_CLEAR_DATA_HOUR);
diff --git a/chrome/browser/ui/webui/options/cookies_view_handler.cc b/chrome/browser/ui/webui/options/cookies_view_handler.cc
index 006a5a5..5faf7fe 100644
--- a/chrome/browser/ui/webui/options/cookies_view_handler.cc
+++ b/chrome/browser/ui/webui/options/cookies_view_handler.cc
@@ -208,7 +208,7 @@ void CookiesViewHandler::EnsureCookiesTreeModelCreated() {
 }
 
 void CookiesViewHandler::UpdateSearchResults(const ListValue* args) {
-  string16 query;
+  base::string16 query;
   if (!args->GetString(0, &query))
     return;
 
diff --git a/chrome/browser/ui/webui/options/core_options_handler.cc b/chrome/browser/ui/webui/options/core_options_handler.cc
index ebc8bcd..cd98a73 100644
--- a/chrome/browser/ui/webui/options/core_options_handler.cc
+++ b/chrome/browser/ui/webui/options/core_options_handler.cc
@@ -415,7 +415,7 @@ void CoreOptionsHandler::HandleFetchPrefs(const ListValue* args) {
   if (!args->Get(0, &callback) || !callback->IsType(base::Value::TYPE_STRING))
     return;
 
-  string16 callback_function;
+  base::string16 callback_function;
   if (!callback->GetAsString(&callback_function))
     return;
 
diff --git a/chrome/browser/ui/webui/options/create_profile_handler.cc b/chrome/browser/ui/webui/options/create_profile_handler.cc
index f88bacc..c6b9c60 100644
--- a/chrome/browser/ui/webui/options/create_profile_handler.cc
+++ b/chrome/browser/ui/webui/options/create_profile_handler.cc
@@ -75,8 +75,8 @@ void CreateProfileHandler::CreateProfile(const ListValue* args) {
   DCHECK(profile_path_being_created_.empty());
   profile_creation_start_time_ = base::TimeTicks::Now();
 
-  string16 name;
-  string16 icon;
+  base::string16 name;
+  base::string16 icon;
   std::string managed_user_id;
   bool create_shortcut = false;
   bool managed_user = false;
@@ -222,7 +222,7 @@ void CreateProfileHandler::OnManagedUserRegistered(
     return;
   }
 
-  string16 error_msg;
+  base::string16 error_msg;
   if (state == GoogleServiceAuthError::INVALID_GAIA_CREDENTIALS ||
       state == GoogleServiceAuthError::USER_NOT_SIGNED_UP ||
       state == GoogleServiceAuthError::ACCOUNT_DELETED ||
@@ -275,8 +275,9 @@ void CreateProfileHandler::CreateShortcutAndShowSuccess(
   profile_creation_type_ = NO_CREATION_IN_PROGRESS;
 }
 
-void CreateProfileHandler::ShowProfileCreationError(Profile* profile,
-                                                    const string16& error) {
+void CreateProfileHandler::ShowProfileCreationError(
+    Profile* profile,
+    const base::string16& error) {
   DCHECK_NE(NO_CREATION_IN_PROGRESS, profile_creation_type_);
   profile_creation_type_ = NO_CREATION_IN_PROGRESS;
   profile_path_being_created_.clear();
@@ -287,7 +288,7 @@ void CreateProfileHandler::ShowProfileCreationError(Profile* profile,
 }
 
 void CreateProfileHandler::ShowProfileCreationWarning(
-    const string16& warning) {
+    const base::string16& warning) {
   DCHECK_EQ(SUPERVISED_PROFILE_CREATION, profile_creation_type_);
   web_ui()->CallJavascriptFunction("BrowserOptions.showCreateProfileWarning",
                                    base::StringValue(warning));
@@ -361,7 +362,7 @@ void CreateProfileHandler::RecordSupervisedProfileCreationMetrics(
   }
 }
 
-string16 CreateProfileHandler::GetProfileCreationErrorMessage(
+base::string16 CreateProfileHandler::GetProfileCreationErrorMessage(
     ProfileCreationErrorType error) const {
   int message_id = -1;
   switch (error) {
diff --git a/chrome/browser/ui/webui/options/create_profile_handler.h b/chrome/browser/ui/webui/options/create_profile_handler.h
index d443df9..2c25b71 100644
--- a/chrome/browser/ui/webui/options/create_profile_handler.h
+++ b/chrome/browser/ui/webui/options/create_profile_handler.h
@@ -109,10 +109,10 @@ class CreateProfileHandler: public OptionsPageUIHandler {
                                     Profile* profile);
 
   // Updates the UI to show an error when creating a profile.
-  void ShowProfileCreationError(Profile* profile, const string16& error);
+  void ShowProfileCreationError(Profile* profile, const base::string16& error);
 
   // Updates the UI to show a non-fatal warning when creating a profile.
-  void ShowProfileCreationWarning(const string16& warning);
+  void ShowProfileCreationWarning(const base::string16& warning);
 
   // Cancels creation of a managed-user profile currently in progress, as
   // indicated by profile_path_being_created_, removing the object and files
@@ -134,7 +134,8 @@ class CreateProfileHandler: public OptionsPageUIHandler {
   void RecordSupervisedProfileCreationMetrics(
       GoogleServiceAuthError::State error_state);
 
-  string16 GetProfileCreationErrorMessage(ProfileCreationErrorType error) const;
+  base::string16 GetProfileCreationErrorMessage(
+      ProfileCreationErrorType error) const;
   std::string GetJavascriptMethodName(ProfileCreationStatus status) const;
 
   bool IsValidExistingManagedUserId(
diff --git a/chrome/browser/ui/webui/options/font_settings_handler.cc b/chrome/browser/ui/webui/options/font_settings_handler.cc
index c0de39a..4e87c11 100644
--- a/chrome/browser/ui/webui/options/font_settings_handler.cc
+++ b/chrome/browser/ui/webui/options/font_settings_handler.cc
@@ -196,7 +196,7 @@ void FontSettingsHandler::FontsListHasLoaded(
     ListValue* font;
     bool has_font = list->GetList(i, &font);
     DCHECK(has_font);
-    string16 value;
+    base::string16 value;
     bool has_value = font->GetString(1, &value);
     DCHECK(has_value);
     bool has_rtl_chars = base::i18n::StringContainsStrongRTLChars(value);
@@ -220,7 +220,7 @@ void FontSettingsHandler::FontsListHasLoaded(
       int cmd_id = it->encoding_id;
       std::string encoding =
       CharacterEncoding::GetCanonicalEncodingNameByCommandId(cmd_id);
-      string16 name = it->encoding_display_name;
+      base::string16 name = it->encoding_display_name;
       bool has_rtl_chars = base::i18n::StringContainsStrongRTLChars(name);
       option->Append(new base::StringValue(encoding));
       option->Append(new base::StringValue(name));
diff --git a/chrome/browser/ui/webui/options/handler_options_handler.cc b/chrome/browser/ui/webui/options/handler_options_handler.cc
index b5a0398..c62edb0 100644
--- a/chrome/browser/ui/webui/options/handler_options_handler.cc
+++ b/chrome/browser/ui/webui/options/handler_options_handler.cc
@@ -185,9 +185,9 @@ void HandlerOptionsHandler::SetDefault(const ListValue* args) {
 
 ProtocolHandler HandlerOptionsHandler::ParseHandlerFromArgs(
     const ListValue* args) const {
-  string16 protocol;
-  string16 url;
-  string16 title;
+  base::string16 protocol;
+  base::string16 url;
+  base::string16 title;
   bool ok = args->GetString(0, &protocol) && args->GetString(1, &url) &&
     args->GetString(2, &title);
   if (!ok)
diff --git a/chrome/browser/ui/webui/options/home_page_overlay_handler.cc b/chrome/browser/ui/webui/options/home_page_overlay_handler.cc
index 29125dc..4496648 100644
--- a/chrome/browser/ui/webui/options/home_page_overlay_handler.cc
+++ b/chrome/browser/ui/webui/options/home_page_overlay_handler.cc
@@ -45,12 +45,12 @@ void HomePageOverlayHandler::GetLocalizedValues(
 
 void HomePageOverlayHandler::RequestAutocompleteSuggestions(
     const base::ListValue* args) {
-  string16 input;
+  base::string16 input;
   CHECK_EQ(args->GetSize(), 1U);
   CHECK(args->GetString(0, &input));
 
   autocomplete_controller_->Start(AutocompleteInput(
-      input, string16::npos, string16(), GURL(),
+      input, base::string16::npos, base::string16(), GURL(),
       AutocompleteInput::INVALID_SPEC, true,
       false, false, AutocompleteInput::ALL_MATCHES));
 }
diff --git a/chrome/browser/ui/webui/options/language_options_handler.cc b/chrome/browser/ui/webui/options/language_options_handler.cc
index c34e614..9883683 100644
--- a/chrome/browser/ui/webui/options/language_options_handler.cc
+++ b/chrome/browser/ui/webui/options/language_options_handler.cc
@@ -66,7 +66,7 @@ ListValue* LanguageOptionsHandler::GetLanguageList() {
   // In theory, we should be able to create a map that is sorted by
   // display names using ICU comparator, but doing it is hard, thus we'll
   // use an auxiliary vector to achieve the same result.
-  typedef std::pair<std::string, string16> LanguagePair;
+  typedef std::pair<std::string, base::string16> LanguagePair;
   typedef std::map<string16, LanguagePair> LanguageMap;
   LanguageMap language_map;
   // The auxiliary vector mentioned above.
@@ -74,10 +74,10 @@ ListValue* LanguageOptionsHandler::GetLanguageList() {
 
   // Build the list of display names, and build the language map.
   for (size_t i = 0; i < language_codes.size(); ++i) {
-    string16 display_name =
+    base::string16 display_name =
         l10n_util::GetDisplayNameForLocale(language_codes[i], app_locale,
                                            false);
-    string16 native_display_name =
+    base::string16 native_display_name =
         l10n_util::GetDisplayNameForLocale(language_codes[i], language_codes[i],
                                            false);
     display_names.push_back(display_name);
@@ -92,12 +92,12 @@ ListValue* LanguageOptionsHandler::GetLanguageList() {
   // Build the language list from the language map.
   ListValue* language_list = new ListValue();
   for (size_t i = 0; i < display_names.size(); ++i) {
-    string16& display_name = display_names[i];
-    string16 adjusted_display_name(display_name);
+    base::string16& display_name = display_names[i];
+    base::string16 adjusted_display_name(display_name);
     base::i18n::AdjustStringForLocaleDirection(&adjusted_display_name);
 
     const LanguagePair& pair = language_map[display_name];
-    string16 adjusted_native_display_name(pair.second);
+    base::string16 adjusted_native_display_name(pair.second);
     base::i18n::AdjustStringForLocaleDirection(&adjusted_native_display_name);
 
     bool has_rtl_chars = base::i18n::StringContainsStrongRTLChars(display_name);
diff --git a/chrome/browser/ui/webui/options/language_options_handler.h b/chrome/browser/ui/webui/options/language_options_handler.h
index 4eafe0f..b75f94f 100644
--- a/chrome/browser/ui/webui/options/language_options_handler.h
+++ b/chrome/browser/ui/webui/options/language_options_handler.h
@@ -33,7 +33,7 @@ class LanguageOptionsHandler : public LanguageOptionsHandlerCommon {
 
  private:
   // LanguageOptionsHandlerCommon implementation.
-  virtual string16 GetProductName() OVERRIDE;
+  virtual base::string16 GetProductName() OVERRIDE;
   virtual void SetApplicationLocale(const std::string& language_code) OVERRIDE;
 
   // Called when the restart button is clicked.
diff --git a/chrome/browser/ui/webui/options/language_options_handler_common.h b/chrome/browser/ui/webui/options/language_options_handler_common.h
index 6cfda8f..65b45cf 100644
--- a/chrome/browser/ui/webui/options/language_options_handler_common.h
+++ b/chrome/browser/ui/webui/options/language_options_handler_common.h
@@ -59,7 +59,7 @@ class LanguageOptionsHandlerCommon
 
  private:
   // Returns the name of the product (ex. "Chrome" or "Chrome OS").
-  virtual string16 GetProductName() = 0;
+  virtual base::string16 GetProductName() = 0;
 
   // Sets the application locale.
   virtual void SetApplicationLocale(const std::string& language_code) = 0;
diff --git a/chrome/browser/ui/webui/options/manage_profile_handler.cc b/chrome/browser/ui/webui/options/manage_profile_handler.cc
index bc1b7de..716cd08 100644
--- a/chrome/browser/ui/webui/options/manage_profile_handler.cc
+++ b/chrome/browser/ui/webui/options/manage_profile_handler.cc
@@ -313,7 +313,7 @@ void ManageProfileHandler::SetProfileIconAndName(const ListValue* args) {
   if (profile->IsManaged())
     return;
 
-  string16 new_profile_name;
+  base::string16 new_profile_name;
   if (!args->GetString(2, &new_profile_name))
     return;
 
@@ -368,7 +368,7 @@ void ManageProfileHandler::ProfileIconSelectionChanged(
   size_t profile_index = cache.GetIndexOfProfileWithPath(profile_file_path);
   if (profile_index == std::string::npos)
     return;
-  string16 gaia_name = cache.GetNameOfProfileAtIndex(profile_index);
+  base::string16 gaia_name = cache.GetNameOfProfileAtIndex(profile_index);
   if (gaia_name.empty())
     return;
 
@@ -405,7 +405,7 @@ void ManageProfileHandler::RequestCreateProfileUpdate(
   Profile* profile = Profile::FromWebUI(web_ui());
   SigninManagerBase* manager =
       SigninManagerFactory::GetForProfile(profile);
-  string16 username = UTF8ToUTF16(manager->GetAuthenticatedUsername());
+  base::string16 username = UTF8ToUTF16(manager->GetAuthenticatedUsername());
   ProfileSyncService* service =
      ProfileSyncServiceFactory::GetForProfile(profile);
   GoogleServiceAuthError::State state = service->GetAuthError().state();
diff --git a/chrome/browser/ui/webui/options/managed_user_import_handler.cc b/chrome/browser/ui/webui/options/managed_user_import_handler.cc
index ae9ef7e..86f9e7f 100644
--- a/chrome/browser/ui/webui/options/managed_user_import_handler.cc
+++ b/chrome/browser/ui/webui/options/managed_user_import_handler.cc
@@ -174,7 +174,7 @@ void ManagedUserImportHandler::SendExistingManagedUsers(
 void ManagedUserImportHandler::ClearManagedUsersAndShowError() {
   web_ui()->CallJavascriptFunction(
       "ManagedUserImportOverlay.receiveExistingManagedUsers");
-  string16 error_message =
+  base::string16 error_message =
       l10n_util::GetStringUTF16(IDS_MANAGED_USER_IMPORT_SIGN_IN_ERROR);
   web_ui()->CallJavascriptFunction("ManagedUserImportOverlay.onError",
                                    base::StringValue(error_message));
diff --git a/chrome/browser/ui/webui/options/media_galleries_handler.cc b/chrome/browser/ui/webui/options/media_galleries_handler.cc
index cef51fe5..3cf35a9 100644
--- a/chrome/browser/ui/webui/options/media_galleries_handler.cc
+++ b/chrome/browser/ui/webui/options/media_galleries_handler.cc
@@ -109,7 +109,7 @@ void MediaGalleriesHandler::HandleAddNewGallery(const base::ListValue* args) {
       new ChromeSelectFilePolicy(web_ui()->GetWebContents()));
   select_file_dialog_->SelectFile(
       ui::SelectFileDialog::SELECT_FOLDER,
-      string16(),  // TODO(estade): a name for the dialog?
+      base::string16(),  // TODO(estade): a name for the dialog?
       base::FilePath(),
       NULL, 0,
       base::FilePath::StringType(),
diff --git a/chrome/browser/ui/webui/options/options_ui.cc b/chrome/browser/ui/webui/options/options_ui.cc
index 61bd0f6..e7c2449 100644
--- a/chrome/browser/ui/webui/options/options_ui.cc
+++ b/chrome/browser/ui/webui/options/options_ui.cc
@@ -206,7 +206,7 @@ void OptionsPageUIHandler::RegisterStrings(
     const OptionsStringResource* resources,
     size_t length) {
   for (size_t i = 0; i < length; ++i) {
-    string16 value;
+    base::string16 value;
     if (resources[i].substitution_id == 0) {
       value = l10n_util::GetStringUTF16(resources[i].id);
     } else {
diff --git a/chrome/browser/ui/webui/options/options_ui_browsertest.cc b/chrome/browser/ui/webui/options/options_ui_browsertest.cc
index f185076..084b248 100644
--- a/chrome/browser/ui/webui/options/options_ui_browsertest.cc
+++ b/chrome/browser/ui/webui/options/options_ui_browsertest.cc
@@ -66,10 +66,10 @@ void OptionsUIBrowserTest::VerifyNavbar() {
 }
 
 void OptionsUIBrowserTest::VerifyTitle() {
-  string16 title =
+  base::string16 title =
       browser()->tab_strip_model()->GetActiveWebContents()->GetTitle();
-  string16 expected_title = l10n_util::GetStringUTF16(IDS_SETTINGS_TITLE);
-  EXPECT_NE(title.find(expected_title), string16::npos);
+  base::string16 expected_title = l10n_util::GetStringUTF16(IDS_SETTINGS_TITLE);
+  EXPECT_NE(title.find(expected_title), base::string16::npos);
 }
 
 // Flaky, see http://crbug.com/119671.
@@ -117,8 +117,8 @@ IN_PROC_BROWSER_TEST_F(OptionsUIBrowserTest, NavigateBackFromOverlayDialog) {
       profile_manager->GenerateNextProfileDirectoryPath(),
       base::Bind(&RunClosureWhenProfileInitialized,
                  run_loop.QuitClosure()),
-                 string16(),
-                 string16(),
+                 base::string16(),
+                 base::string16(),
                  std::string());
   run_loop.Run();
 
diff --git a/chrome/browser/ui/webui/options/password_manager_handler.cc b/chrome/browser/ui/webui/options/password_manager_handler.cc
index 3805f1d..b605282 100644
--- a/chrome/browser/ui/webui/options/password_manager_handler.cc
+++ b/chrome/browser/ui/webui/options/password_manager_handler.cc
@@ -120,8 +120,9 @@ void PasswordManagerHandler::HandleRequestShowPassword(const ListValue* args) {
   password_manager_presenter_.RequestShowPassword(static_cast<size_t>(index));
 }
 
-void PasswordManagerHandler::ShowPassword(size_t index,
-                                          const string16& password_value) {
+void PasswordManagerHandler::ShowPassword(
+    size_t index,
+    const base::string16& password_value) {
   // Call back the front end to reveal the password.
   web_ui()->CallJavascriptFunction(
       "PasswordManager.showPassword",
@@ -138,7 +139,7 @@ void PasswordManagerHandler::SetPasswordList(
     bool show_passwords) {
   ListValue entries;
   languages_ = GetProfile()->GetPrefs()->GetString(prefs::kAcceptLanguages);
-  string16 placeholder(ASCIIToUTF16("        "));
+  base::string16 placeholder(ASCIIToUTF16("        "));
   for (size_t i = 0; i < password_list.size(); ++i) {
     ListValue* entry = new ListValue();
     entry->Append(new StringValue(net::FormatUrl(password_list[i]->origin,
@@ -149,7 +150,7 @@ void PasswordManagerHandler::SetPasswordList(
     } else {
       // Use a placeholder value with the same length as the password.
       entry->Append(new StringValue(
-          string16(password_list[i]->password_value.length(), ' ')));
+          base::string16(password_list[i]->password_value.length(), ' ')));
     }
     entries.Append(entry);
   }
diff --git a/chrome/browser/ui/webui/options/password_manager_handler.h b/chrome/browser/ui/webui/options/password_manager_handler.h
index c25b05c..11ec857 100644
--- a/chrome/browser/ui/webui/options/password_manager_handler.h
+++ b/chrome/browser/ui/webui/options/password_manager_handler.h
@@ -29,7 +29,7 @@ class PasswordManagerHandler : public OptionsPageUIHandler,
 
   // PasswordUIView implementation.
   virtual Profile* GetProfile() OVERRIDE;
-  virtual void ShowPassword(size_t index, const string16& password_value)
+  virtual void ShowPassword(size_t index, const base::string16& password_value)
       OVERRIDE;
   virtual void SetPasswordList(
       const ScopedVector<autofill::PasswordForm>& password_list,
diff --git a/chrome/browser/ui/webui/options/search_engine_manager_handler.cc b/chrome/browser/ui/webui/options/search_engine_manager_handler.cc
index e0d67c0..ed168b6 100644
--- a/chrome/browser/ui/webui/options/search_engine_manager_handler.cc
+++ b/chrome/browser/ui/webui/options/search_engine_manager_handler.cc
@@ -247,8 +247,8 @@ void SearchEngineManagerHandler::EditSearchEngine(const ListValue* args) {
 
 void SearchEngineManagerHandler::OnEditedKeyword(
     TemplateURL* template_url,
-    const string16& title,
-    const string16& keyword,
+    const base::string16& title,
+    const base::string16& keyword,
     const std::string& url) {
   DCHECK(!url.empty());
   if (template_url)
@@ -263,8 +263,8 @@ void SearchEngineManagerHandler::CheckSearchEngineInfoValidity(
 {
   if (!edit_controller_.get())
     return;
-  string16 name;
-  string16 keyword;
+  base::string16 name;
+  base::string16 keyword;
   std::string url;
   std::string modelIndex;
   if (!args->GetString(ENGINE_NAME, &name) ||
@@ -294,8 +294,8 @@ void SearchEngineManagerHandler::EditCancelled(const ListValue* args) {
 void SearchEngineManagerHandler::EditCompleted(const ListValue* args) {
   if (!edit_controller_.get())
     return;
-  string16 name;
-  string16 keyword;
+  base::string16 name;
+  base::string16 keyword;
   std::string url;
   if (!args->GetString(ENGINE_NAME, &name) ||
       !args->GetString(ENGINE_KEYWORD, &keyword) ||
diff --git a/chrome/browser/ui/webui/options/search_engine_manager_handler.h b/chrome/browser/ui/webui/options/search_engine_manager_handler.h
index 337a7da..2057d82 100644
--- a/chrome/browser/ui/webui/options/search_engine_manager_handler.h
+++ b/chrome/browser/ui/webui/options/search_engine_manager_handler.h
@@ -38,8 +38,8 @@ class SearchEngineManagerHandler : public OptionsPageUIHandler,
 
   // EditSearchEngineControllerDelegate implementation.
   virtual void OnEditedKeyword(TemplateURL* template_url,
-                               const string16& title,
-                               const string16& keyword,
+                               const base::string16& title,
+                               const base::string16& keyword,
                                const std::string& url) OVERRIDE;
 
   virtual void RegisterMessages() OVERRIDE;
diff --git a/chrome/browser/ui/webui/options/startup_pages_handler.cc b/chrome/browser/ui/webui/options/startup_pages_handler.cc
index 343b2a6..e46e9ce 100644
--- a/chrome/browser/ui/webui/options/startup_pages_handler.cc
+++ b/chrome/browser/ui/webui/options/startup_pages_handler.cc
@@ -224,12 +224,12 @@ void StartupPagesHandler::CancelChanges(const ListValue* args) {
 
 void StartupPagesHandler::RequestAutocompleteSuggestions(
     const ListValue* args) {
-  string16 input;
+  base::string16 input;
   CHECK_EQ(args->GetSize(), 1U);
   CHECK(args->GetString(0, &input));
 
   autocomplete_controller_->Start(AutocompleteInput(
-      input, string16::npos, string16(), GURL(),
+      input, base::string16::npos, base::string16(), GURL(),
       AutocompleteInput::INVALID_SPEC, true,
       false, false, AutocompleteInput::ALL_MATCHES));
 }
diff --git a/chrome/browser/ui/webui/plugins_ui.cc b/chrome/browser/ui/webui/plugins_ui.cc
index dc42f0d..0564ecd 100644
--- a/chrome/browser/ui/webui/plugins_ui.cc
+++ b/chrome/browser/ui/webui/plugins_ui.cc
@@ -106,7 +106,7 @@ content::WebUIDataSource* CreatePluginsUIHTMLSource() {
   return source;
 }
 
-string16 PluginTypeToString(int type) {
+base::string16 PluginTypeToString(int type) {
   // The type is stored as an |int|, but doing the switch on the right
   // enumeration type gives us better build-time error checking (if someone adds
   // a new type).
@@ -121,7 +121,7 @@ string16 PluginTypeToString(int type) {
       return l10n_util::GetStringUTF16(IDS_PLUGINS_PPAPI_UNSANDBOXED);
   }
   NOTREACHED();
-  return string16();
+  return base::string16();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -240,7 +240,7 @@ void PluginsDOMHandler::HandleEnablePluginMessage(const ListValue* args) {
 
   PluginPrefs* plugin_prefs = PluginPrefs::GetForProfile(profile).get();
   if (is_group_str == "true") {
-    string16 group_name;
+    base::string16 group_name;
     if (!args->GetString(0, &group_name)) {
       NOTREACHED();
       return;
@@ -249,9 +249,10 @@ void PluginsDOMHandler::HandleEnablePluginMessage(const ListValue* args) {
     plugin_prefs->EnablePluginGroup(enable, group_name);
     if (enable) {
       // See http://crbug.com/50105 for background.
-      string16 adobereader = ASCIIToUTF16(
-           PluginMetadata::kAdobeReaderGroupName);
-      string16 internalpdf = ASCIIToUTF16(ChromeContentClient::kPDFPluginName);
+      base::string16 adobereader = ASCIIToUTF16(
+          PluginMetadata::kAdobeReaderGroupName);
+      base::string16 internalpdf =
+          ASCIIToUTF16(ChromeContentClient::kPDFPluginName);
       if (group_name == adobereader)
         plugin_prefs->EnablePluginGroup(false, internalpdf);
       else if (group_name == internalpdf)
@@ -352,7 +353,7 @@ void PluginsDOMHandler::PluginsLoaded(
     ListValue* plugin_files = new ListValue();
     scoped_ptr<PluginMetadata> plugin_metadata(
         plugin_finder->GetPluginMetadata(*group_plugins[0]));
-    string16 group_name = plugin_metadata->name();
+    base::string16 group_name = plugin_metadata->name();
     std::string group_identifier = plugin_metadata->identifier();
     bool group_enabled = false;
     bool all_plugins_enabled_by_policy = true;
diff --git a/chrome/browser/ui/webui/policy_ui.cc b/chrome/browser/ui/webui/policy_ui.cc
index 3d93dc5..259e67b 100644
--- a/chrome/browser/ui/webui/policy_ui.cc
+++ b/chrome/browser/ui/webui/policy_ui.cc
@@ -139,11 +139,12 @@ void GetStatusFromCore(const policy::CloudPolicyCore* core,
 
   bool no_error = store->status() == policy::CloudPolicyStore::STATUS_OK &&
                   client && client->status() == policy::DM_STATUS_SUCCESS;
-  string16 status = store->status() == policy::CloudPolicyStore::STATUS_OK &&
-                    client && client->status() != policy::DM_STATUS_SUCCESS ?
-                        policy::FormatDeviceManagementStatus(client->status()) :
-                        policy::FormatStoreStatus(store->status(),
-                                                  store->validation_status());
+  base::string16 status =
+      store->status() == policy::CloudPolicyStore::STATUS_OK &&
+      client && client->status() != policy::DM_STATUS_SUCCESS ?
+                policy::FormatDeviceManagementStatus(client->status()) :
+                policy::FormatStoreStatus(store->status(),
+                                          store->validation_status());
   const em::PolicyData* policy = store->policy();
   std::string client_id = policy ? policy->device_id() : std::string();
   std::string username = policy ? policy->username() : std::string();
@@ -684,7 +685,7 @@ void PolicyUIHandler::GetPolicyValues(const policy::PolicyMap& map,
       value->SetString("level", "recommended");
     else
       value->SetString("level", "mandatory");
-    string16 error = errors->GetErrors(entry->first);
+    base::string16 error = errors->GetErrors(entry->first);
     if (!error.empty())
       value->SetString("error", error);
     values->Set(entry->first, value);
diff --git a/chrome/browser/ui/webui/print_preview/print_preview_handler.cc b/chrome/browser/ui/webui/print_preview/print_preview_handler.cc
index 5af78f4..e832afe 100644
--- a/chrome/browser/ui/webui/print_preview/print_preview_handler.cc
+++ b/chrome/browser/ui/webui/print_preview/print_preview_handler.cc
@@ -758,7 +758,7 @@ void PrintPreviewHandler::HandlePrint(const ListValue* args) {
 #endif
 
   scoped_refptr<base::RefCountedBytes> data;
-  string16 title;
+  base::string16 title;
   if (!GetPreviewDataAndTitle(&data, &title)) {
     // Nothing to print, no preview available.
     return;
@@ -824,7 +824,7 @@ void PrintPreviewHandler::PrintToPdf() {
     PrintPreviewUI* print_preview_ui = static_cast<PrintPreviewUI*>(
         web_ui()->GetController());
     // Pre-populating select file dialog with print job title.
-    string16 print_job_title_utf16 = print_preview_ui->initiator_title();
+    base::string16 print_job_title_utf16 = print_preview_ui->initiator_title();
 
 #if defined(OS_WIN)
     base::FilePath::StringType print_job_title(print_job_title_utf16);
@@ -918,7 +918,7 @@ void PrintPreviewHandler::PrintWithCloudPrintDialog() {
   ReportStats();
 
   scoped_refptr<base::RefCountedBytes> data;
-  string16 title;
+  base::string16 title;
   if (!GetPreviewDataAndTitle(&data, &title)) {
     // Nothing to print, no preview available.
     return;
@@ -931,7 +931,7 @@ void PrintPreviewHandler::PrintWithCloudPrintDialog() {
       modal_parent,
       data.get(),
       title,
-      string16(),
+      base::string16(),
       std::string("application/pdf"));
 
   // Once the cloud print dialog comes up we're no longer in a background
@@ -1213,7 +1213,7 @@ void PrintPreviewHandler::SelectFile(const base::FilePath& default_filename) {
       this, new ChromeSelectFilePolicy(preview_web_contents())),
   select_file_dialog_->SelectFile(
       ui::SelectFileDialog::SELECT_SAVEAS_FILE,
-      string16(),
+      base::string16(),
       sticky_settings->save_path()->Append(default_filename),
       &file_type_info,
       0,
@@ -1258,7 +1258,7 @@ void PrintPreviewHandler::FileSelected(const base::FilePath& path,
 
 void PrintPreviewHandler::PostPrintToPdfTask() {
   scoped_refptr<base::RefCountedBytes> data;
-  string16 title;
+  base::string16 title;
   if (!GetPreviewDataAndTitle(&data, &title)) {
     NOTREACHED() << "Preview data was checked before file dialog.";
     return;
@@ -1294,7 +1294,7 @@ void PrintPreviewHandler::ClearInitiatorDetails() {
 
 bool PrintPreviewHandler::GetPreviewDataAndTitle(
     scoped_refptr<base::RefCountedBytes>* data,
-    string16* title) const {
+    base::string16* title) const {
   PrintPreviewUI* print_preview_ui = static_cast<PrintPreviewUI*>(
       web_ui()->GetController());
   scoped_refptr<base::RefCountedBytes> tmp_data;
@@ -1434,7 +1434,7 @@ void PrintPreviewHandler::StartPrivetLocalPrint(
   privet_local_print_operation_->SetTicket(print_ticket);
 
   scoped_refptr<base::RefCountedBytes> data;
-  string16 title;
+  base::string16 title;
 
   if (!GetPreviewDataAndTitle(&data, &title)) {
     base::FundamentalValue http_code_value(-1);
diff --git a/chrome/browser/ui/webui/print_preview/print_preview_handler.h b/chrome/browser/ui/webui/print_preview/print_preview_handler.h
index c364b32..a35df5d 100644
--- a/chrome/browser/ui/webui/print_preview/print_preview_handler.h
+++ b/chrome/browser/ui/webui/print_preview/print_preview_handler.h
@@ -242,7 +242,7 @@ class PrintPreviewHandler
   void GetNumberFormatAndMeasurementSystem(base::DictionaryValue* settings);
 
   bool GetPreviewDataAndTitle(scoped_refptr<base::RefCountedBytes>* data,
-                              string16* title) const;
+                              base::string16* title) const;
 
 #if defined(USE_CUPS)
   void SaveCUPSColorSetting(const base::DictionaryValue* settings);
diff --git a/chrome/browser/ui/webui/print_preview/print_preview_ui.cc b/chrome/browser/ui/webui/print_preview/print_preview_ui.cc
index 0209e97..44c6171 100644
--- a/chrome/browser/ui/webui/print_preview/print_preview_ui.cc
+++ b/chrome/browser/ui/webui/print_preview/print_preview_ui.cc
@@ -209,7 +209,7 @@ content::WebUIDataSource* CreatePrintPreviewUISource() {
                              IDS_PRINT_PREVIEW_PAGE_LABEL_SINGULAR);
   source->AddLocalizedString("printPreviewPageLabelPlural",
                              IDS_PRINT_PREVIEW_PAGE_LABEL_PLURAL);
-  const string16 shortcut_text(UTF8ToUTF16(kAdvancedPrintShortcut));
+  const base::string16 shortcut_text(UTF8ToUTF16(kAdvancedPrintShortcut));
 #if defined(OS_CHROMEOS)
   source->AddString(
       "systemDialogOption",
@@ -400,7 +400,7 @@ int PrintPreviewUI::GetAvailableDraftPageCount() {
 }
 
 void PrintPreviewUI::SetInitiatorTitle(
-    const string16& job_title) {
+    const base::string16& job_title) {
   initiator_title_ = job_title;
 }
 
diff --git a/chrome/browser/ui/webui/print_preview/print_preview_ui.h b/chrome/browser/ui/webui/print_preview/print_preview_ui.h
index 33fcd80..5d68c3b 100644
--- a/chrome/browser/ui/webui/print_preview/print_preview_ui.h
+++ b/chrome/browser/ui/webui/print_preview/print_preview_ui.h
@@ -53,9 +53,9 @@ class PrintPreviewUI : public ConstrainedWebDialogUI {
   int GetAvailableDraftPageCount();
 
   // Setters
-  void SetInitiatorTitle(const string16& initiator_title);
+  void SetInitiatorTitle(const base::string16& initiator_title);
 
-  string16 initiator_title() { return initiator_title_; }
+  base::string16 initiator_title() { return initiator_title_; }
 
   bool source_is_modifiable() { return source_is_modifiable_; }
 
@@ -191,7 +191,7 @@ class PrintPreviewUI : public ConstrainedWebDialogUI {
 
   // Store the initiator title, used for populating the print preview dialog
   // title.
-  string16 initiator_title_;
+  base::string16 initiator_title_;
 
   // Keeps track of whether OnClosePrintPreviewDialog() has been called or not.
   bool dialog_closed_;
diff --git a/chrome/browser/ui/webui/print_preview/print_preview_ui_browsertest.cc b/chrome/browser/ui/webui/print_preview/print_preview_ui_browsertest.cc
index d4f64be..d642b0f 100644
--- a/chrome/browser/ui/webui/print_preview/print_preview_ui_browsertest.cc
+++ b/chrome/browser/ui/webui/print_preview/print_preview_ui_browsertest.cc
@@ -96,7 +96,7 @@ IN_PROC_BROWSER_TEST_F(PrintPreviewTest, WindowedNPAPIPluginHidden) {
                                                true);
 
   // First load the page and wait for the NPAPI plugin's window to display.
-  string16 expected_title(ASCIIToUTF16("ready"));
+  base::string16 expected_title(ASCIIToUTF16("ready"));
   content::WebContents* tab =
       browser()->tab_strip_model()->GetActiveWebContents();
   content::TitleWatcher title_watcher(tab, expected_title);
diff --git a/chrome/browser/ui/webui/set_as_default_browser_ui.cc b/chrome/browser/ui/webui/set_as_default_browser_ui.cc
index 89184e2..d088966d 100644
--- a/chrome/browser/ui/webui/set_as_default_browser_ui.cc
+++ b/chrome/browser/ui/webui/set_as_default_browser_ui.cc
@@ -224,7 +224,7 @@ class SetAsDefaultBrowserDialogImpl : public ui::WebDialogDelegate,
  protected:
   // Overridden from WebDialogDelegate:
   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;
diff --git a/chrome/browser/ui/webui/signin/profile_signin_confirmation_dialog.h b/chrome/browser/ui/webui/signin/profile_signin_confirmation_dialog.h
index ce803be..232b48d 100644
--- a/chrome/browser/ui/webui/signin/profile_signin_confirmation_dialog.h
+++ b/chrome/browser/ui/webui/signin/profile_signin_confirmation_dialog.h
@@ -53,7 +53,7 @@ class ProfileSigninConfirmationDialog : public ui::WebDialogDelegate {
 
   // WebDialogDelegate implementation.
   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<content::WebUIMessageHandler*>* handlers) const OVERRIDE;
diff --git a/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc b/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
index f74eaa0..53e48fe 100644
--- a/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
+++ b/chrome/browser/ui/webui/signin/user_manager_screen_handler.cc
@@ -132,8 +132,9 @@ class UserManagerScreenHandler::ProfileUpdateObserver
     user_manager_handler_->SendUserList();
   }
 
-  virtual void OnProfileWasRemoved(const base::FilePath& profile_path,
-                                   const string16& profile_name) OVERRIDE {
+  virtual void OnProfileWasRemoved(
+      const base::FilePath& profile_path,
+      const base::string16& profile_name) OVERRIDE {
     // TODO(noms): Change 'SendUserList' to 'removeUser' JS-call when
     // UserManager is able to find pod belonging to removed user.
     user_manager_handler_->SendUserList();
@@ -145,8 +146,9 @@ class UserManagerScreenHandler::ProfileUpdateObserver
     // will be called.
   }
 
-  virtual void OnProfileNameChanged(const base::FilePath& profile_path,
-                                    const string16& old_profile_name) OVERRIDE {
+  virtual void OnProfileNameChanged(
+      const base::FilePath& profile_path,
+      const base::string16& old_profile_name) OVERRIDE {
     user_manager_handler_->SendUserList();
   }
 
@@ -254,8 +256,8 @@ void UserManagerScreenHandler::HandleLaunchGuest(const base::ListValue* args) {
 }
 
 void UserManagerScreenHandler::HandleLaunchUser(const base::ListValue* args) {
-  string16 emailAddress;
-  string16 displayName;
+  base::string16 emailAddress;
+  base::string16 displayName;
 
   if (!args->GetString(0, &emailAddress) ||
       !args->GetString(1, &displayName)) {
@@ -364,10 +366,12 @@ void UserManagerScreenHandler::GetLocalizedValues(
 
   // Strings needed for the user_pod_template public account div, but not ever
   // actually displayed for desktop users.
-  localized_strings->SetString("publicAccountReminder", string16());
-  localized_strings->SetString("publicAccountEnter", string16());
-  localized_strings->SetString("publicAccountEnterAccessibleName", string16());
-  localized_strings->SetString("multiple-signin-banner-text", string16());
+  localized_strings->SetString("publicAccountReminder", base::string16());
+  localized_strings->SetString("publicAccountEnter", base::string16());
+  localized_strings->SetString("publicAccountEnterAccessibleName",
+                               base::string16());
+  localized_strings->SetString("multiple-signin-banner-text",
+                               base::string16());
  }
 
 void UserManagerScreenHandler::SendUserList() {
diff --git a/chrome/browser/ui/webui/signin/user_manager_ui_browsertest.cc b/chrome/browser/ui/webui/signin/user_manager_ui_browsertest.cc
index d1cb865..96c2366 100644
--- a/chrome/browser/ui/webui/signin/user_manager_ui_browsertest.cc
+++ b/chrome/browser/ui/webui/signin/user_manager_ui_browsertest.cc
@@ -41,7 +41,7 @@ IN_PROC_BROWSER_TEST_F(UserManagerUIBrowserTest, PageLoads) {
   content::WebContents* web_contents =
       browser()->tab_strip_model()->GetActiveWebContents();
 
-  string16 title = web_contents->GetTitle();
+  base::string16 title = web_contents->GetTitle();
   EXPECT_EQ(l10n_util::GetStringUTF16(IDS_USER_MANAGER_SCREEN_TITLE), title);
 
   // If the page has loaded correctly, then there should be an account picker.
diff --git a/chrome/browser/ui/webui/sync_internals_ui_unittest.cc b/chrome/browser/ui/webui/sync_internals_ui_unittest.cc
index 0183aef..02ad293 100644
--- a/chrome/browser/ui/webui/sync_internals_ui_unittest.cc
+++ b/chrome/browser/ui/webui/sync_internals_ui_unittest.cc
@@ -48,7 +48,7 @@ class TestSyncWebUI: public WebUI {
       : WebUI(web_contents) {}
   virtual ~TestSyncWebUI() {}
 
-  MOCK_METHOD1(ExecuteJavascript, void(const string16&));
+  MOCK_METHOD1(ExecuteJavascript, void(const base::string16&));
 };
 
 // Tests with non-NULL ProfileSyncService.
diff --git a/chrome/browser/ui/webui/sync_setup_handler.cc b/chrome/browser/ui/webui/sync_setup_handler.cc
index 80e4c9c..8d595ec 100644
--- a/chrome/browser/ui/webui/sync_setup_handler.cc
+++ b/chrome/browser/ui/webui/sync_setup_handler.cc
@@ -199,7 +199,7 @@ void SyncSetupHandler::GetStaticLocalizedValues(
     content::WebUI* web_ui) {
   DCHECK(localized_strings);
 
-  string16 product_name(GetStringUTF16(IDS_PRODUCT_NAME));
+  base::string16 product_name(GetStringUTF16(IDS_PRODUCT_NAME));
   localized_strings->SetString(
       "chooseDataTypesInstructions",
       GetStringFUTF16(IDS_SYNC_CHOOSE_DATATYPES_INSTRUCTIONS, product_name));
@@ -367,7 +367,8 @@ void SyncSetupHandler::DisplayConfigureSync(bool show_advanced,
   base::Time passphrase_time = service->GetExplicitPassphraseTime();
   syncer::PassphraseType passphrase_type = service->GetPassphraseType();
   if (!passphrase_time.is_null()) {
-    string16 passphrase_time_str = base::TimeFormatShortDate(passphrase_time);
+    base::string16 passphrase_time_str =
+        base::TimeFormatShortDate(passphrase_time);
     args.SetString(
         "enterPassphraseBody",
         GetStringFUTF16(IDS_SYNC_ENTER_PASSPHRASE_BODY_WITH_DATE,
diff --git a/chrome/browser/ui/webui/sync_setup_handler_unittest.cc b/chrome/browser/ui/webui/sync_setup_handler_unittest.cc
index e40ccc3..b72c06b 100644
--- a/chrome/browser/ui/webui/sync_setup_handler_unittest.cc
+++ b/chrome/browser/ui/webui/sync_setup_handler_unittest.cc
@@ -196,10 +196,10 @@ class TestWebUI : public content::WebUI {
   virtual ui::ScaleFactor GetDeviceScaleFactor() const OVERRIDE {
     return ui::SCALE_FACTOR_100P;
   }
-  virtual const string16& GetOverriddenTitle() const OVERRIDE {
+  virtual const base::string16& GetOverriddenTitle() const OVERRIDE {
     return temp_string_;
   }
-  virtual void OverrideTitle(const string16& title) OVERRIDE {}
+  virtual void OverrideTitle(const base::string16& title) OVERRIDE {}
   virtual content::PageTransition GetLinkTransitionType() const OVERRIDE {
     return content::PAGE_TRANSITION_LINK;
   }
@@ -240,7 +240,7 @@ class TestWebUI : public content::WebUI {
   const std::vector<CallData>& call_data() { return call_data_; }
  private:
   std::vector<CallData> call_data_;
-  string16 temp_string_;
+  base::string16 temp_string_;
 };
 
 class TestingSyncSetupHandler : public SyncSetupHandler {
diff --git a/chrome/browser/ui/webui/task_manager/task_manager_dialog.cc b/chrome/browser/ui/webui/task_manager/task_manager_dialog.cc
index 221df31..b4228cf 100644
--- a/chrome/browser/ui/webui/task_manager/task_manager_dialog.cc
+++ b/chrome/browser/ui/webui/task_manager/task_manager_dialog.cc
@@ -63,7 +63,7 @@ class TaskManagerDialogImpl : public WebDialogDelegate {
   virtual ui::ModalType GetDialogModalType() const OVERRIDE {
     return ui::MODAL_TYPE_NONE;
   }
-  virtual string16 GetDialogTitle() const OVERRIDE {
+  virtual base::string16 GetDialogTitle() const OVERRIDE {
     return l10n_util::GetStringUTF16(IDS_TASK_MANAGER_TITLE);
   }
   virtual std::string GetDialogName() const OVERRIDE {
diff --git a/chrome/browser/ui/webui/task_manager/task_manager_handler.cc b/chrome/browser/ui/webui/task_manager/task_manager_handler.cc
index f9dc4f9..81aa206 100644
--- a/chrome/browser/ui/webui/task_manager/task_manager_handler.cc
+++ b/chrome/browser/ui/webui/task_manager/task_manager_handler.cc
@@ -110,7 +110,7 @@ void TaskManagerHandler::RegisterMessages() {
 
 static int parseIndex(const Value* value) {
   int index = -1;
-  string16 string16_index;
+  base::string16 base::string16_index;
   double double_index;
   if (value->GetAsString(&string16_index)) {
     bool converted = base::StringToInt(string16_index, &index);
diff --git a/chrome/browser/ui/webui/translate_internals/translate_internals_ui.cc b/chrome/browser/ui/webui/translate_internals/translate_internals_ui.cc
index d09e512..d3c2429 100644
--- a/chrome/browser/ui/webui/translate_internals/translate_internals_ui.cc
+++ b/chrome/browser/ui/webui/translate_internals/translate_internals_ui.cc
@@ -37,7 +37,7 @@ void GetLanguages(base::DictionaryValue* dict) {
   for (std::vector<std::string>::iterator it = language_codes.begin();
        it != language_codes.end(); ++it) {
     const std::string& lang_code = *it;
-    string16 lang_name =
+    base::string16 lang_name =
         l10n_util::GetDisplayNameForLocale(lang_code, app_locale, false);
     dict->SetString(lang_code, lang_name);
   }
diff --git a/chrome/browser/ui/webui/version_handler.cc b/chrome/browser/ui/webui/version_handler.cc
index b46de41..6074c10 100644
--- a/chrome/browser/ui/webui/version_handler.cc
+++ b/chrome/browser/ui/webui/version_handler.cc
@@ -23,8 +23,8 @@ namespace {
 
 // Retrieves the executable and profile paths on the FILE thread.
 void GetFilePaths(const base::FilePath& profile_path,
-                  string16* exec_path_out,
-                  string16* profile_path_out) {
+                  base::string16* exec_path_out,
+                  base::string16* profile_path_out) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
 
   base::FilePath executable_path = base::MakeAbsoluteFilePath(
@@ -72,8 +72,8 @@ void VersionHandler::HandleRequestVersionInfo(const ListValue* args) {
 
   // Grab the executable path on the FILE thread. It is returned in
   // OnGotFilePaths.
-  string16* exec_path_buffer = new string16;
-  string16* profile_path_buffer = new string16;
+  base::string16* exec_path_buffer = new base::string16;
+  base::string16* profile_path_buffer = new base::string16;
   content::BrowserThread::PostTaskAndReply(
       content::BrowserThread::FILE, FROM_HERE,
           base::Bind(&GetFilePaths, Profile::FromWebUI(web_ui())->GetPath(),
@@ -115,7 +115,7 @@ void VersionHandler::HandleRequestVersionInfo(const ListValue* args) {
 }
 
 void VersionHandler::OnGotFilePaths(string16* executable_path_data,
-                                    string16* profile_path_data) {
+                                    base::string16* profile_path_data) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 
   StringValue exec_path(*executable_path_data);
@@ -130,7 +130,7 @@ void VersionHandler::OnGotPlugins(
   std::vector<content::WebPluginInfo> info_array;
   content::PluginService::GetInstance()->GetPluginInfoArray(
       GURL(), content::kFlashPluginSwfMimeType, false, &info_array, NULL);
-  string16 flash_version =
+  base::string16 flash_version =
       l10n_util::GetStringUTF16(IDS_PLUGINS_DISABLED_PLUGIN);
   PluginPrefs* plugin_prefs =
       PluginPrefs::GetForProfile(Profile::FromWebUI(web_ui())).get();
diff --git a/chrome/browser/ui/webui/version_handler.h b/chrome/browser/ui/webui/version_handler.h
index 2fc65d4..a5affc2 100644
--- a/chrome/browser/ui/webui/version_handler.h
+++ b/chrome/browser/ui/webui/version_handler.h
@@ -30,7 +30,7 @@ class VersionHandler : public content::WebUIMessageHandler {
   // Callback which handles returning the executable and profile paths to the
   // front end.
   void OnGotFilePaths(string16* executable_path_data,
-                      string16* profile_path_data);
+                      base::string16* profile_path_data);
 
   // Callback for GetPlugins which responds to the page with the Flash version.
   // This also initiates the OS Version load on ChromeOS.
diff --git a/chrome/browser/ui/webui/web_ui_test_handler.cc b/chrome/browser/ui/webui/web_ui_test_handler.cc
index 2cbcf1a..0c347e4 100644
--- a/chrome/browser/ui/webui/web_ui_test_handler.cc
+++ b/chrome/browser/ui/webui/web_ui_test_handler.cc
@@ -27,25 +27,26 @@ WebUITestHandler::WebUITestHandler()
       is_waiting_(false) {
 }
 
-void WebUITestHandler::PreloadJavaScript(const string16& js_text,
+void WebUITestHandler::PreloadJavaScript(const base::string16& js_text,
                                          RenderViewHost* preload_host) {
   DCHECK(preload_host);
   preload_host->Send(new ChromeViewMsg_WebUIJavaScript(
-      preload_host->GetRoutingID(), string16(), js_text, 0,
+      preload_host->GetRoutingID(), base::string16(), js_text, 0,
       false));
 }
 
-void WebUITestHandler::RunJavaScript(const string16& js_text) {
+void WebUITestHandler::RunJavaScript(const base::string16& js_text) {
   web_ui()->GetWebContents()->GetRenderViewHost()->ExecuteJavascriptInWebFrame(
-      string16(), js_text);
+      base::string16(), js_text);
 }
 
-bool WebUITestHandler::RunJavaScriptTestWithResult(const string16& js_text) {
+bool WebUITestHandler::RunJavaScriptTestWithResult(
+    const base::string16& js_text) {
   test_succeeded_ = false;
   run_test_succeeded_ = false;
   RenderViewHost* rvh = web_ui()->GetWebContents()->GetRenderViewHost();
   rvh->ExecuteJavascriptInWebFrameCallbackResult(
-      string16(),  // frame_xpath
+      base::string16(),  // frame_xpath
       js_text,
       base::Bind(&WebUITestHandler::JavaScriptComplete,
                  base::Unretained(this)));
diff --git a/chrome/browser/ui/webui/web_ui_test_handler.h b/chrome/browser/ui/webui/web_ui_test_handler.h
index 91b6321..04cd7c6 100644
--- a/chrome/browser/ui/webui/web_ui_test_handler.h
+++ b/chrome/browser/ui/webui/web_ui_test_handler.h
@@ -25,15 +25,15 @@ class WebUITestHandler : public content::WebUIMessageHandler {
 
   // Sends a message through |preload_host| with the |js_text| to preload at the
   // appropriate time before the onload call is made.
-  void PreloadJavaScript(const string16& js_text,
+  void PreloadJavaScript(const base::string16& js_text,
                          content::RenderViewHost* preload_host);
 
   // Runs |js_text| in this object's WebUI frame. Does not wait for any result.
-  void RunJavaScript(const string16& js_text);
+  void RunJavaScript(const base::string16& js_text);
 
   // Runs |js_text| in this object's WebUI frame. Waits for result, logging an
   // error message on failure. Returns test pass/fail.
-  bool RunJavaScriptTestWithResult(const string16& js_text);
+  bool RunJavaScriptTestWithResult(const base::string16& js_text);
 
   // WebUIMessageHandler overrides.
   // Add test handlers to the current WebUI object.
diff --git a/chrome/browser/ui/webui/welcome_ui_android.cc b/chrome/browser/ui/webui/welcome_ui_android.cc
index 7a1579d..b5321a8 100644
--- a/chrome/browser/ui/webui/welcome_ui_android.cc
+++ b/chrome/browser/ui/webui/welcome_ui_android.cc
@@ -54,7 +54,7 @@ WelcomeUI::WelcomeUI(content::WebUI* web_ui)
   bool tos_visible = tab && tab->ShouldWelcomePageLinkToTermsOfService();
   html_source->AddBoolean("tosVisible", tos_visible);
 
-  string16 tos_html;
+  base::string16 tos_html;
   if (tos_visible) {
     std::string privacy_notice_url =
         base::StringPrintf(kPrivacyNoticeBaseURL, locale.c_str());