Mozart: Improve internal scene graph representation.

services/gfx/compositor/scene_state.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SERVICES_GFX_COMPOSITOR_SCENE_STATE_H_
 #define SERVICES_GFX_COMPOSITOR_SCENE_STATE_H_
 
 #include <memory>
 #include <string>
 #include <unordered_map>
@@ skipping 16 matching lines @@
 class SceneState {
  public:
   SceneState(mojo::gfx::composition::SceneTokenPtr scene_token,
              const std::string& label);
   ~SceneState();
 
   base::WeakPtr<SceneState> GetWeakPtr() { return weak_factory_.GetWeakPtr(); }
 
   // Gets the token used to refer to this scene globally.
   // Caller does not obtain ownership of the token.
-  mojo::gfx::composition::SceneToken* scene_token() {
-    return scene_def_.scene_token();
+  const mojo::gfx::composition::SceneToken* scene_token() {
+    return scene_token_.get();
   }
 
   // Gets or sets the scene listener interface.
   mojo::gfx::composition::SceneListener* scene_listener() {
     return scene_listener_.get();
   }
   void set_scene_listener(mojo::gfx::composition::SceneListenerPtr listener) {
     scene_listener_ = listener.Pass();
   }
 
   // Sets the associated scene implementation and takes ownership of it.
   void set_scene_impl(mojo::gfx::composition::Scene* impl) {
     scene_impl_.reset(impl);
   }
 
   // Gets the underlying scene definition, never null.
   SceneDef* scene_def() { return &scene_def_; }
 
   void AddSceneFrameCallback(const SceneFrameCallback& callback);
   void DispatchSceneFrameCallbacks(
       const mojo::gfx::composition::FrameInfo& frame_info);
 
-  const std::string& label() { return scene_def_.label(); }
-  std::string FormattedLabel() { return scene_def_.FormattedLabel(); }
-
  private:
+  mojo::gfx::composition::SceneTokenPtr scene_token_;
   std::unique_ptr<mojo::gfx::composition::Scene> scene_impl_;
   mojo::gfx::composition::SceneListenerPtr scene_listener_;
   std::vector<SceneFrameCallback> pending_frame_callbacks_;
 
   SceneDef scene_def_;
 
   base::WeakPtrFactory<SceneState> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SceneState);
 };
 
 std::ostream& operator<<(std::ostream& os, SceneState* scene_state);
 
 }  // namespace compositor
 
 #endif  // SERVICES_GFX_COMPOSITOR_SCENE_STATE_H_