[Cast] VideoFrameFactory interface to vend frames with encoder affinity.

media/cast/cast_sender.h

Index: media/cast/cast_sender.h
diff --git a/media/cast/cast_sender.h b/media/cast/cast_sender.h
index 7615c28602c8f58052f4f7bf024c4eba79bc6bcc..841e1ba143ae97ef0c4fb3e15cbb571f6bdb4672 100644
--- a/media/cast/cast_sender.h
+++ b/media/cast/cast_sender.h
@@ -36,6 +36,19 @@ class VideoFrameInput : public base::RefCountedThreadSafe<VideoFrameInput> {
       const scoped_refptr<media::VideoFrame>& video_frame,
       const base::TimeTicks& capture_time) = 0;
 
+  // Creates a |VideoFrame| optimized for the encoder. When available, these
+  // frames offer performance benefits, such as memory copy elimination. The
+  // format is guaranteed to be I420 or NV12.
+  //
+  // Not every encoder supports this method. Use |ShouldCreateOptimizedFrame|
+  // to determine if you can and should use this method. Calling
+  // this method when |ShouldCreateOptimizedFrame| is false will CHECK.
+  virtual scoped_refptr<VideoFrame> CreateOptimizedFrame(
+      base::TimeDelta timestamp) = 0;
+
+  // Returns true if the encoder supports creating optimized frames.
+  virtual bool SupportsCreateOptimizedFrame() const = 0;
+
  protected:
   virtual ~VideoFrameInput() {}