Add OVERRIDE to content/.

content/renderer/media/audio_message_filter.h

Index: content/renderer/media/audio_message_filter.h
diff --git a/content/renderer/media/audio_message_filter.h b/content/renderer/media/audio_message_filter.h
index b37e45e9058de9fa56e164bbc0a32c287b7ebb89..5888a865ff32990ab0bc08e6d0cfaea5635ffddc 100644
--- a/content/renderer/media/audio_message_filter.h
+++ b/content/renderer/media/audio_message_filter.h
@@ -69,10 +69,10 @@ class CONTENT_EXPORT AudioMessageFilter
   FRIEND_TEST_ALL_PREFIXES(AudioMessageFilterTest, Delegates);
 
   // IPC::ChannelProxy::MessageFilter override. Called on IO thread.
-  virtual bool OnMessageReceived(const IPC::Message& message);
-  virtual void OnFilterAdded(IPC::Channel* channel);
-  virtual void OnFilterRemoved();
-  virtual void OnChannelClosing();
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+  virtual void OnFilterAdded(IPC::Channel* channel) OVERRIDE;
+  virtual void OnFilterRemoved() OVERRIDE;
+  virtual void OnChannelClosing() OVERRIDE;
 
   // Received when browser process wants more audio packet.
   void OnRequestPacket(int stream_id, AudioBuffersState buffers_state);