Add OVERRIDE to chrome/browser/sync/.

chrome/browser/sync/engine/post_commit_message_command.h

-// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
+// 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_BROWSER_SYNC_ENGINE_POST_COMMIT_MESSAGE_COMMAND_H_
 #define CHROME_BROWSER_SYNC_ENGINE_POST_COMMIT_MESSAGE_COMMAND_H_
 #pragma once
 
+#include "base/compiler_specific.h"
 #include "chrome/browser/sync/engine/syncer_command.h"
 
 namespace browser_sync {
 
 class PostCommitMessageCommand : public SyncerCommand {
  public:
   PostCommitMessageCommand();
   virtual ~PostCommitMessageCommand();
 
   // SyncerCommand implementation.
-  virtual void ExecuteImpl(sessions::SyncSession* session);
+  virtual void ExecuteImpl(sessions::SyncSession* session) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PostCommitMessageCommand);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_ENGINE_POST_COMMIT_MESSAGE_COMMAND_H_