Add video-rendering to mojo media pipeline.

media/base/renderer.h

Index: media/base/renderer.h
diff --git a/media/base/renderer.h b/media/base/renderer.h
index 89e349a9350d1c44564690a84bdc2391589e78d2..d4851b1f83a5eef756dd3d0264448b6854d71b5a 100644
--- a/media/base/renderer.h
+++ b/media/base/renderer.h
@@ -36,6 +36,7 @@ class MEDIA_EXPORT Renderer {
   // Permanent callbacks:
   // - |statistics_cb|: Executed periodically with rendering statistics.
   // - |buffering_state_cb|: Executed when buffering state is changed.
+  // - |natural_size_changed_cb|: Executed when video natural size is changed.
   // - |ended_cb|: Executed when rendering has reached the end of stream.
   // - |error_cb|: Executed if any error was encountered after initialization.
   // - |waiting_for_decryption_key_cb|: Executed whenever the key needed to
@@ -45,6 +46,7 @@ class MEDIA_EXPORT Renderer {
       const PipelineStatusCB& init_cb,
       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 base::Closure& waiting_for_decryption_key_cb) = 0;