Add OVERRIDE to chrome/browser/sync/.

chrome/browser/sync/engine/apply_updates_command.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_BROWSER_SYNC_ENGINE_APPLY_UPDATES_COMMAND_H_
 #define CHROME_BROWSER_SYNC_ENGINE_APPLY_UPDATES_COMMAND_H_
 #pragma once
 
+#include "base/compiler_specific.h"
 #include "chrome/browser/sync/engine/model_changing_syncer_command.h"
 
 namespace browser_sync {
 
 class ApplyUpdatesCommand : public ModelChangingSyncerCommand {
  public:
   ApplyUpdatesCommand();
   virtual ~ApplyUpdatesCommand();
 
   // ModelChangingSyncerCommand implementation.
-  virtual void ModelChangingExecuteImpl(sessions::SyncSession* session);
+  virtual void ModelChangingExecuteImpl(
+      sessions::SyncSession* session) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ApplyUpdatesCommand);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_ENGINE_APPLY_UPDATES_COMMAND_H_