Implement temporary reference assignment with DisplayCompositor.

services/ui/ws/window_server.h

 // Copyright 2014 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_UI_WS_WINDOW_SERVER_H_
 #define SERVICES_UI_WS_WINDOW_SERVER_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 265 matching lines @@
   // hierarchy.
   void UpdateNativeCursorFromMouseLocation(ServerWindow* window);
 
   // Updates the native cursor if the cursor is currently inside |window|. This
   // is run in response to events that change the mouse cursor properties of
   // |window|.
   void UpdateNativeCursorIfOver(ServerWindow* window);
 
   bool IsUserInHighContrastMode(const UserId& user) const;
 
+  // Finds the parent ServerWindow of |window| that is expected to be backed by
+  // a CompositorFrameSink.
+  ServerWindow* FindCompositorFrameSinkParent(ServerWindow* window);
+
   // Overridden from ServerWindowDelegate:
   ServerWindow* GetRootWindow(const ServerWindow* window) override;
 
   // Overridden from ServerWindowObserver:
   void OnWindowDestroyed(ServerWindow* window) override;
   void OnWillChangeWindowHierarchy(ServerWindow* window,
                                    ServerWindow* new_parent,
                                    ServerWindow* old_parent) override;
   void OnWindowHierarchyChanged(ServerWindow* window,
                                 ServerWindow* new_parent,
@@ skipping 83 matching lines @@
   // State for rendering into a Surface.
   cc::mojom::DisplayCompositorPtr display_compositor_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowServer);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_WINDOW_SERVER_H_