Mozart: Generalize frame scheduling.

services/gfx/compositor/compositor_engine.h

Index: services/gfx/compositor/compositor_engine.h
diff --git a/services/gfx/compositor/compositor_engine.h b/services/gfx/compositor/compositor_engine.h
index a1a73293ea7125b057a2fa07d910d13432b4e32e..e425c9ad49cb63b334a53432a8ed49c76aab552e 100644
--- a/services/gfx/compositor/compositor_engine.h
+++ b/services/gfx/compositor/compositor_engine.h
@@ -57,7 +57,7 @@ class CompositorEngine {
 
   // Schedules a frame callback.
   void ScheduleFrame(SceneState* scene_state,
-                     const SceneFrameCallback& callback);
+                     const FrameCallback& callback);
 
   // RENDERER REQUESTS
 
@@ -72,6 +72,10 @@ class CompositorEngine {
   // Destroys |renderer_state| if an error occurs.
   void ClearRootScene(RendererState* renderer_state);
 
+  // Schedules a frame callback.
+  void ScheduleFrame(RendererState* renderer_state,
+                     const FrameCallback& callback);
+
   // Performs a hit test.
   void HitTest(
       RendererState* renderer_state,