Add video-rendering to mojo media pipeline.

media/base/video_renderer.h

Index: media/base/video_renderer.h
diff --git a/media/base/video_renderer.h b/media/base/video_renderer.h
index ddd47777daa5d4133fb8a66faf6e64a00fe141a8..84487ae55af3a5f4fb31cbc4c2b0f1aa5d66bad5 100644
--- a/media/base/video_renderer.h
+++ b/media/base/video_renderer.h
@@ -44,6 +44,8 @@ class MEDIA_EXPORT VideoRenderer {
   // |buffering_state_cb| is executed when video rendering has either run out of
   // data or has enough data to continue playback.
   //
+  // |natural_size_changed_cb| is executed when video natural size changes.
+  //
   // |ended_cb| is executed when video rendering has reached the end of stream.
   //
   // |error_cb| is executed if an error was encountered after initialization.
@@ -59,6 +61,7 @@ class MEDIA_EXPORT VideoRenderer {
       CdmContext* cdm_context,
       const StatisticsCB& statistics_cb,
       const BufferingStateCB& buffering_state_cb,
+      const NaturalSizeChangedCB& natural_size_changed_cb,
       const base::Closure& ended_cb,
       const PipelineStatusCB& error_cb,
       const TimeSource::WallClockTimeCB& wall_clock_time_cb,