Add video-rendering to mojo media pipeline.

media/mojo/services/mojo_renderer_service.h

Index: media/mojo/services/mojo_renderer_service.h
diff --git a/media/mojo/services/mojo_renderer_service.h b/media/mojo/services/mojo_renderer_service.h
index 89c63add37aec3fc68d9062dfd7ce5fe644e32e5..a22da272913141c306fb21c47ee5f9e737a95048 100644
--- a/media/mojo/services/mojo_renderer_service.h
+++ b/media/mojo/services/mojo_renderer_service.h
@@ -18,6 +18,10 @@
 #include "media/mojo/interfaces/renderer.mojom.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 
+namespace gfx {
+class Size;
+}  // namespace gfx
+
 namespace media {
 
 class DemuxerStreamProviderShim;
@@ -79,6 +83,9 @@ class MojoRendererService : interfaces::Renderer {
   // TODO(tim): Need old and new.
   void OnBufferingStateChanged(BufferingState new_buffering_state);
 
+  // Callback executed by video renderer when video natural size changes.
+  void OnNaturalSizeChanged(const gfx::Size& size);
+
   // Callback executed when a renderer has ended.
   void OnRendererEnded();