[Cast] Compute utilization metrics and add performance overlay.

media/cast/sender/video_encoder_impl.h

Index: media/cast/sender/video_encoder_impl.h
diff --git a/media/cast/sender/video_encoder_impl.h b/media/cast/sender/video_encoder_impl.h
index b31efa67b98b4e9e9af422bb59010737961dc19e..a8cf2075bfec15662eaa3ca32d6fa3a26952d640 100644
--- a/media/cast/sender/video_encoder_impl.h
+++ b/media/cast/sender/video_encoder_impl.h
@@ -26,9 +26,6 @@ class VideoEncoderImpl : public VideoEncoder {
     int bit_rate;
   };
 
-  typedef base::Callback<void(scoped_ptr<EncodedFrame>)>
-      FrameEncodedCallback;
-
   // Returns true if VideoEncoderImpl can be used with the given |video_config|.
   static bool IsSupported(const VideoSenderConfig& video_config);