Update {virtual,override} to follow C++11 style in ppapi.

ppapi/proxy/flash_menu_resource.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 PPAPI_PROXY_FLASH_MENU_RESOURCE_H_
 #define PPAPI_PROXY_FLASH_MENU_RESOURCE_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "ppapi/proxy/plugin_resource.h"
 #include "ppapi/shared_impl/tracked_callback.h"
 #include "ppapi/thunk/ppb_flash_menu_api.h"
 
 struct PP_Flash_Menu;
 
 namespace ppapi {
 namespace proxy {
 
 class FlashMenuResource
     : public PluginResource,
       public thunk::PPB_Flash_Menu_API {
  public:
   // You must call Initialize after construction.
   FlashMenuResource(Connection connection, PP_Instance instance);
-  virtual ~FlashMenuResource();
+  ~FlashMenuResource() override;
 
   // Returns true on success. False means that this object can not be used.
   // This has to be separate from the constructor because the menu data could
   // be invalid.
   bool Initialize(const PP_Flash_Menu* menu_data);
 
   // Resource overrides.
-  virtual thunk::PPB_Flash_Menu_API* AsPPB_Flash_Menu_API() override;
+  thunk::PPB_Flash_Menu_API* AsPPB_Flash_Menu_API() override;
 
   // PPB_Flash_Menu_API.
-  virtual int32_t Show(const PP_Point* location,
-                       int32_t* selected_id,
-                       scoped_refptr<TrackedCallback> callback) override;
+  int32_t Show(const PP_Point* location,
+               int32_t* selected_id,
+               scoped_refptr<TrackedCallback> callback) override;
 
  private:
-  virtual void OnReplyReceived(const proxy::ResourceMessageReplyParams& params,
-                               const IPC::Message& msg) override;
+  void OnReplyReceived(const proxy::ResourceMessageReplyParams& params,
+                       const IPC::Message& msg) override;
 
   void OnShowReply(
       const proxy::ResourceMessageReplyParams& params,
       int32_t selected_id);
 
   int* selected_id_dest_;
   scoped_refptr<TrackedCallback> callback_;
 
   DISALLOW_COPY_AND_ASSIGN(FlashMenuResource);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_FLASH_MENU_RESOURCE_H_