Mozart: Directly associate the renderer with the view tree.

services/gfx/compositor/renderer_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_RENDERER_STATE_H_
 #define SERVICES_GFX_COMPOSITOR_RENDERER_STATE_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 35 matching lines @@
   SceneState* root_scene() { return root_scene_; }
   uint32_t root_scene_version() { return root_scene_version_; }
   const mojo::Rect& root_scene_viewport() { return root_scene_viewport_; }
 
   // Sets the root scene and clears the current frame and cached dependencies.
   // If different, invalidates the snapshot and returns true.
   bool SetRootScene(SceneState* scene,
                     uint32_t version,
                     const mojo::Rect& viewport);
 
+  // Resets the root scene and clears the current frame and cached dependencies.
+  // If different, invalidates the snapshot and returns true.
+  bool ResetRootScene();
+
   // The currently composited frame, may be null if none.
   const std::shared_ptr<RenderFrame>& frame() { return frame_; }
 
   // The current scene graph snapshot, may be null if none.
   const std::unique_ptr<Snapshot>& snapshot() { return snapshot_; }
 
   // Returns true if the renderer has a snapshot and it is valid.
   // This implies that |frame()| is also non-null.
   bool valid() { return snapshot_ && snapshot_->valid(); }
 
@@ skipping 24 matching lines @@
   base::WeakPtrFactory<RendererState> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererState);
 };
 
 std::ostream& operator<<(std::ostream& os, RendererState* renderer_state);
 
 }  // namespace compositor
 
 #endif  // SERVICES_GFX_COMPOSITOR_RENDERER_STATE_H_