Add video-rendering to mojo media pipeline.

media/mojo/interfaces/renderer.mojom

Index: media/mojo/interfaces/renderer.mojom
diff --git a/media/mojo/interfaces/renderer.mojom b/media/mojo/interfaces/renderer.mojom
index 422bc72e02d05744924fbebf2bff21325050a22d..2cfda96197af823436878c94d0e2e263dc0c0307 100644
--- a/media/mojo/interfaces/renderer.mojom
+++ b/media/mojo/interfaces/renderer.mojom
@@ -6,6 +6,7 @@ module media.interfaces;
 
 import "media/mojo/interfaces/demuxer_stream.mojom";
 import "media/mojo/interfaces/media_types.mojom";
+import "ui/mojo/geometry/geometry.mojom";
 
 interface Renderer {
   // Initializes the Renderer with one or both of an audio and video stream,
@@ -43,8 +44,12 @@ interface RendererClient {
   OnTimeUpdate(int64 time_usec, int64 max_time_usec);
 
   // Called to report buffering state changes, see media_types.mojom.
+  // TODO(alokp): Rename it to OnBufferingStateChanged for consistency.
   OnBufferingStateChange(BufferingState state);
 
+  // Called to report video natural size change.
+  OnNaturalSizeChanged(mojo.Size size);
+
   // Executed when rendering has reached the end of stream.
   OnEnded();