Convert string16 to base::string16 in content.

content/shell/browser/shell_javascript_dialog_manager.h

Index: content/shell/browser/shell_javascript_dialog_manager.h
diff --git a/content/shell/browser/shell_javascript_dialog_manager.h b/content/shell/browser/shell_javascript_dialog_manager.h
index 763736f58a7395fc4f47bb85e41fce2ac5e0ad48..5bcfb658499eaa4f7de9b53a634e8c5ef4f970b5 100644
--- a/content/shell/browser/shell_javascript_dialog_manager.h
+++ b/content/shell/browser/shell_javascript_dialog_manager.h
@@ -25,14 +25,14 @@ class ShellJavaScriptDialogManager : public JavaScriptDialogManager {
       const GURL& origin_url,
       const std::string& accept_lang,
       JavaScriptMessageType javascript_message_type,
-      const string16& message_text,
-      const string16& default_prompt_text,
+      const base::string16& message_text,
+      const base::string16& default_prompt_text,
       const DialogClosedCallback& callback,
       bool* did_suppress_message) OVERRIDE;
 
   virtual void RunBeforeUnloadDialog(
       WebContents* web_contents,
-      const string16& message_text,
+      const base::string16& message_text,
       bool is_reload,
       const DialogClosedCallback& callback) OVERRIDE;