Fix warnings when compiling with clang

content/renderer/media/webmediaplayer_proxy_impl_android.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 CONTENT_RENDERER_MEDIA_WEBMEDIAPLAYER_PROXY_IMPL_ANDROID_H_
 #define CONTENT_RENDERER_MEDIA_WEBMEDIAPLAYER_PROXY_IMPL_ANDROID_H_
 
 #include <map>
 
 #include "content/public/renderer/render_view_observer.h"
@@ skipping 14 matching lines @@
       public webkit_media::WebMediaPlayerProxyAndroid {
  public:
   // Construct a WebMediaPlayerProxyImplAndroid object for the |render_view|.
   // |manager| is passed to this class so that it can find the right
   // WebMediaPlayerImplAndroid using player IDs.
   WebMediaPlayerProxyImplAndroid(
       RenderView* render_view,
       webkit_media::WebMediaPlayerManagerAndroid* manager);
   virtual ~WebMediaPlayerProxyImplAndroid();
 
-  bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
+  virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
 
   // Methods inherited from WebMediaPlayerProxyAndroid.
   virtual void Initialize(int player_id, const std::string& url,
                           const std::string& first_party_for_cookies) OVERRIDE;
   virtual void Start(int player_id) OVERRIDE;
   virtual void Pause(int player_id) OVERRIDE;
   virtual void Seek(int player_id, base::TimeDelta time) OVERRIDE;
   virtual void ReleaseResources(int player_id) OVERRIDE;
   virtual void DestroyPlayer(int player_id) OVERRIDE;
 
@@ skipping 11 matching lines @@
   void OnMediaPlayerReleased(int player_id);
 
   webkit_media::WebMediaPlayerManagerAndroid* manager_;
 
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerProxyImplAndroid);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_WEBMEDIAPLAYER_PROXY_IMPL_ANDROID_H_