Add video-rendering to mojo media pipeline.

media/blink/video_frame_compositor.h

Index: media/blink/video_frame_compositor.h
diff --git a/media/blink/video_frame_compositor.h b/media/blink/video_frame_compositor.h
index 893fa7c43688f5a3218b9a88a2e402b061e498b7..b992d79dfb87190a0f3bc3af19146063a5209903 100644
--- a/media/blink/video_frame_compositor.h
+++ b/media/blink/video_frame_compositor.h
@@ -54,21 +54,12 @@ class MEDIA_BLINK_EXPORT VideoFrameCompositor
   // |compositor_task_runner| is the task runner on which this class will live,
   // though it may be constructed on any thread.
   //
-  // |natural_size_changed_cb| is run with the new natural size of the video
-  // frame whenever a change in natural size is detected. It is not called the
-  // first time UpdateCurrentFrame() is called. Run on the same thread as the
-  // caller of UpdateCurrentFrame().
-  //
   // |opacity_changed_cb| is run when a change in opacity is detected. It *is*
   // called the first time UpdateCurrentFrame() is called. Run on the same
   // thread as the caller of UpdateCurrentFrame().
-  //
-  // TODO(dalecurtis): Investigate the inconsistency between the callbacks with
-  // respect to why we don't call |natural_size_changed_cb| on the first frame.
-  // I suspect it was for historical reasons that no longer make sense.
+  // TODO(alokp): Move |opacity_changed_cb| to Renderer.
   VideoFrameCompositor(
       const scoped_refptr<base::SingleThreadTaskRunner>& compositor_task_runner,
-      const base::Callback<void(gfx::Size)>& natural_size_changed_cb,
       const base::Callback<void(bool)>& opacity_changed_cb);
 
   // Destruction must happen on the compositor thread; Stop() must have been
@@ -130,8 +121,8 @@ class MEDIA_BLINK_EXPORT VideoFrameCompositor
   // must be used to change |rendering_| state.
   void OnRendererStateUpdate(bool new_state);
 
-  // Handles setting of |current_frame_| and fires |natural_size_changed_cb_|
-  // and |opacity_changed_cb_| when the frame properties changes.
+  // Handles setting of |current_frame_| and fires |opacity_changed_cb_|
+  // when the frame properties changes.
   bool ProcessNewFrame(const scoped_refptr<VideoFrame>& frame);
 
   // Called by |background_rendering_timer_| when enough time elapses where we
@@ -140,7 +131,7 @@ class MEDIA_BLINK_EXPORT VideoFrameCompositor
 
   // If |callback_| is available, calls Render() with the provided properties.
   // Updates |is_background_rendering_|, |last_interval_|, and resets
-  // |background_rendering_timer_|.  Ensures that natural size and opacity
+  // |background_rendering_timer_|.  Ensures that opacity
   // changes are correctly fired.  Returns true if there's a new frame available
   // via GetCurrentFrame().
   bool CallRender(base::TimeTicks deadline_min,
@@ -150,8 +141,7 @@ class MEDIA_BLINK_EXPORT VideoFrameCompositor
   scoped_refptr<base::SingleThreadTaskRunner> compositor_task_runner_;
   scoped_ptr<base::TickClock> tick_clock_;
 
-  // These callbacks are executed on the compositor thread.
-  const base::Callback<void(gfx::Size)> natural_size_changed_cb_;
+  // This callback is executed on the compositor thread.
   const base::Callback<void(bool)> opacity_changed_cb_;
 
   // Allows tests to disable the background rendering task.