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

content/renderer/media/android/renderer_demuxer_android.h

Index: content/renderer/media/android/renderer_demuxer_android.h
diff --git a/content/renderer/media/android/renderer_demuxer_android.h b/content/renderer/media/android/renderer_demuxer_android.h
index 2fddc862048308d389d8586e641e03f0f134b38a..29469edebb600d77a66963618d54979f6ad8177e 100644
--- a/content/renderer/media/android/renderer_demuxer_android.h
+++ b/content/renderer/media/android/renderer_demuxer_android.h
@@ -44,7 +44,7 @@ class RendererDemuxerAndroid : public IPC::MessageFilter {
   void RemoveDelegate(int demuxer_client_id);
 
   // IPC::MessageFilter overrides.
-  virtual bool OnMessageReceived(const IPC::Message& message) override;
+  bool OnMessageReceived(const IPC::Message& message) override;
 
   // media::DemuxerAndroidClient "implementation".
   //
@@ -61,7 +61,7 @@ class RendererDemuxerAndroid : public IPC::MessageFilter {
 
  protected:
   friend class base::RefCountedThreadSafe<RendererDemuxerAndroid>;
-  virtual ~RendererDemuxerAndroid();
+  ~RendererDemuxerAndroid() override;
 
  private:
   void DispatchMessage(const IPC::Message& message);