Add base:: to string16 in chrome_frame/.

chrome_frame/find_dialog.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_FRAME_FIND_DIALOG_H_
 #define CHROME_FRAME_FIND_DIALOG_H_
 
 #include <atlbase.h>
 #include <atlwin.h>
 
@@ skipping 32 matching lines @@
   // Since the message loop we expect to run in isn't going to be nicely
   // calling IsDialogMessage(), we need to hook the wnd proc and call it
   // ourselves. See http://support.microsoft.com/kb/q187988/
   bool InstallMessageHook();
   bool UninstallMessageHook();
   static LRESULT CALLBACK GetMsgProc(int code, WPARAM wparam, LPARAM lparam);
   static HHOOK msg_hook_;
 
   // Store the text we searched for last to determine whether we are doing a
   // "Find" or a "Find Next".
-  string16 last_find_text_;
+  base::string16 last_find_text_;
 
   // We don't own these, and they must exist at least as long as we do.
   scoped_refptr<ChromeFrameAutomationClient> automation_client_;
 };
 
 #endif  // CHROME_FRAME_FIND_DIALOG_H_