Standardize usage of virtual/override/final in cc/

cc/layers/video_frame_provider_client_impl.h

Index: cc/layers/video_frame_provider_client_impl.h
diff --git a/cc/layers/video_frame_provider_client_impl.h b/cc/layers/video_frame_provider_client_impl.h
index c2d65997cf4508fbe7199a218b75b14007c0a531..b6eb86f0fef659d4b4928cde60e416c3cb4026af 100644
--- a/cc/layers/video_frame_provider_client_impl.h
+++ b/cc/layers/video_frame_provider_client_impl.h
@@ -39,14 +39,14 @@ class VideoFrameProviderClientImpl
 
   // VideoFrameProvider::Client implementation. These methods are all callable
   // on any thread.
-  virtual void StopUsingProvider() override;
-  virtual void DidReceiveFrame() override;
-  virtual void DidUpdateMatrix(const float* matrix) override;
+  void StopUsingProvider() override;
+  void DidReceiveFrame() override;
+  void DidUpdateMatrix(const float* matrix) override;
 
  private:
   explicit VideoFrameProviderClientImpl(VideoFrameProvider* provider);
   friend class base::RefCounted<VideoFrameProviderClientImpl>;
-  virtual ~VideoFrameProviderClientImpl();
+  ~VideoFrameProviderClientImpl() override;
 
   VideoLayerImpl* active_video_layer_;