Add OVERRIDE to chrome/renderer.

chrome/renderer/chrome_mock_render_thread.h

 // Copyright (c) 2011 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_RENDERER_CHROME_MOCK_RENDER_THREAD_H_
 #define CHROME_RENDERER_CHROME_MOCK_RENDER_THREAD_H_
 #pragma once
 
 #include <string>
 
@@ skipping 31 matching lines @@
 
   // Cancel print preview when print preview has |page| remaining pages.
   void set_print_preview_cancel_page_number(int page);
 
   // Get the number of pages to generate for print preview.
   int print_preview_pages_remaining();
 
  private:
   // Overrides base class implementation to add custom handling for
   // print and extensions.
-  virtual bool OnMessageReceived(const IPC::Message& msg);
+  virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
 
   // The callee expects to be returned a valid channel_id.
   void OnMsgOpenChannelToExtension(
       int routing_id, const std::string& extension_id,
       const std::string& source_extension_id,
       const std::string& target_extension_id, int* port_id);
 
 #if defined(OS_CHROMEOS)
   void OnAllocateTempFileForPrinting(base::FileDescriptor* renderer_fd,
                                      int* browser_fd);
@@ skipping 30 matching lines @@
 
   // Simulates cancelling print preview if |print_preview_pages_remaining_|
   // equals this.
   int print_preview_cancel_page_number_;
 
   // Number of pages to generate for print preview.
   int print_preview_pages_remaining_;
 };
 
 #endif  // CHROME_RENDERER_CHROME_MOCK_RENDER_THREAD_H_