Mozart: Ensure time always runs forward.

services/gfx/compositor/scene_state.h

Index: services/gfx/compositor/scene_state.h
diff --git a/services/gfx/compositor/scene_state.h b/services/gfx/compositor/scene_state.h
index 47526e301267979b6e6f255646b1f9b8258d9895..c5f07efb0d3443b378558ea51057e5e72591145c 100644
--- a/services/gfx/compositor/scene_state.h
+++ b/services/gfx/compositor/scene_state.h
@@ -34,8 +34,8 @@ class SceneState {
 
   // Gets the token used to refer to this scene globally.
   // Caller does not obtain ownership of the token.
-  const mojo::gfx::composition::SceneToken* scene_token() {
-    return scene_token_.get();
+  const mojo::gfx::composition::SceneToken& scene_token() {
+    return *scene_token_;
   }
 
   // Gets or sets the scene listener interface.