Mozart: Directly associate the renderer with the view tree.

services/gfx/compositor/compositor_engine.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_COMPOSITOR_H_
 #define SERVICES_GFX_COMPOSITOR_COMPOSITOR_H_
 
 #include <unordered_map>
 #include <vector>
 
@@ skipping 49 matching lines @@
 
   // RENDERER REQUESTS
 
   // Sets the root scene.
   // Destroys |renderer_state| if an error occurs.
   void SetRootScene(RendererState* renderer_state,
                     mojo::gfx::composition::SceneTokenPtr scene_token,
                     uint32 scene_version,
                     mojo::RectPtr viewport);
 
+  // Resets the root scene.
+  // Destroys |renderer_state| if an error occurs.
+  void ResetRootScene(RendererState* renderer_state);
+
   // Performs a hit test.
   void HitTest(
       RendererState* renderer_state,
       mojo::PointPtr point,
       const mojo::gfx::composition::HitTester::HitTestCallback& callback);
 
  private:
   void OnSceneConnectionError(SceneState* scene_state);
   void DestroyScene(SceneState* scene_state);
 
@@ skipping 48 matching lines @@
   std::vector<RendererState*> renderers_;
 
   base::WeakPtrFactory<CompositorEngine> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CompositorEngine);
 };
 
 }  // namespace compositor
 
 #endif  // SERVICES_GFX_COMPOSITOR_COMPOSITOR_H_