Add OVERRIDE to chrome/browser/extensions/.

chrome/browser/extensions/extension_module.h

-// Copyright (c) 2010 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_EXTENSIONS_EXTENSION_MODULE_H__
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_MODULE_H__
 #pragma once
 
 #include "chrome/browser/extensions/extension_function.h"
 
 class ExtensionPrefs;
 
 class SetUpdateUrlDataFunction : public SyncExtensionFunction {
  protected:
-  virtual bool RunImpl();
+  virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION_NAME("extension.setUpdateUrlData");
 
  private:
   ExtensionPrefs* extension_prefs();
 };
 
 class IsAllowedIncognitoAccessFunction : public SyncExtensionFunction {
  protected:
-  virtual bool RunImpl();
+  virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION_NAME("extension.isAllowedIncognitoAccess");
 };
 
 class IsAllowedFileSchemeAccessFunction : public SyncExtensionFunction {
  protected:
-  virtual bool RunImpl();
+  virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION_NAME("extension.isAllowedFileSchemeAccess");
 };
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_MODULE_H__