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

content/browser/media/android/browser_demuxer_android.h

Index: content/browser/media/android/browser_demuxer_android.h
diff --git a/content/browser/media/android/browser_demuxer_android.h b/content/browser/media/android/browser_demuxer_android.h
index 1e7f799e68acb6365e7173d25300c450f9f68306..407e0b3288663ab1c37541a92a266b6f9a270db5 100644
--- a/content/browser/media/android/browser_demuxer_android.h
+++ b/content/browser/media/android/browser_demuxer_android.h
@@ -21,9 +21,9 @@ class CONTENT_EXPORT BrowserDemuxerAndroid : public BrowserMessageFilter {
   BrowserDemuxerAndroid();
 
   // BrowserMessageFilter overrides.
-  virtual void OverrideThreadForMessage(const IPC::Message& message,
-                                        BrowserThread::ID* thread) override;
-  virtual bool OnMessageReceived(const IPC::Message& message) override;
+  void OverrideThreadForMessage(const IPC::Message& message,
+                                BrowserThread::ID* thread) override;
+  bool OnMessageReceived(const IPC::Message& message) override;
 
   // Returns an uninitialized demuxer implementation associated with
   // |demuxer_client_id|, which can be used to communicate with the real demuxer
@@ -32,7 +32,7 @@ class CONTENT_EXPORT BrowserDemuxerAndroid : public BrowserMessageFilter {
 
  protected:
   friend class base::RefCountedThreadSafe<BrowserDemuxerAndroid>;
-  virtual ~BrowserDemuxerAndroid();
+  ~BrowserDemuxerAndroid() override;
 
  private:
   class Internal;