Convert string16 to base::string16 in content.

content/public/browser/web_ui.h

Index: content/public/browser/web_ui.h
diff --git a/content/public/browser/web_ui.h b/content/public/browser/web_ui.h
index 3dad85c2a0d8937e68a5c0c1ff5f9fa794ec1b9a..5427673ad437c484dc708460bdfa87c12840efc4 100644
--- a/content/public/browser/web_ui.h
+++ b/content/public/browser/web_ui.h
@@ -41,7 +41,7 @@ class CONTENT_EXPORT WebUI {
 
   // Returns JavaScript code that, when executed, calls the function specified
   // by |function_name| with the arguments specified in |arg_list|.
-  static string16 GetJavascriptCall(
+  static base::string16 GetJavascriptCall(
       const std::string& function_name,
       const std::vector<const base::Value*>& arg_list);
 
@@ -60,8 +60,8 @@ class CONTENT_EXPORT WebUI {
   // Gets a custom tab title provided by the Web UI. If there is no title
   // override, the string will be empty which should trigger the default title
   // behavior for the tab.
-  virtual const string16& GetOverriddenTitle() const = 0;
-  virtual void OverrideTitle(const string16& title) = 0;
+  virtual const base::string16& GetOverriddenTitle() const = 0;
+  virtual void OverrideTitle(const base::string16& title) = 0;
 
   // Returns the transition type that should be used for link clicks on this
   // Web UI. This will default to LINK but may be overridden.