chromeos: changes how DisplayManagerObservers are notified

ash/mus/bridge/shell_port_mash.h

 // Copyright 2016 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 ASH_MUS_BRIDGE_SHELL_PORT_MASH_H_
 #define ASH_MUS_BRIDGE_SHELL_PORT_MASH_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
 
 #include "ash/display/window_tree_host_manager.h"
 #include "ash/shell_port.h"
 #include "base/macros.h"
 
 namespace aura {
 class WindowTreeClient;
 }
 
 namespace views {
 class PointerWatcherEventRouter;
 }
 
 namespace ash {
 
 class AcceleratorControllerDelegateAura;
+class DisplaySynchronizer;
 class PointerWatcherAdapter;
 class RootWindowController;
 
 namespace mus {
 
 class AcceleratorControllerDelegateMus;
 class AcceleratorControllerRegistrar;
 class ImmersiveHandlerFactoryMus;
 class WindowManager;
 class ShellPortMashTestApi;
@@ skipping 115 matching lines @@
   // TODO(sky): remove this once mash supports simple display management.
   aura::Window* primary_root_window_;
 
   // Only one of |mash_state_| or |mus_state_| is created, depending upon
   // Config.
   std::unique_ptr<MashSpecificState> mash_state_;
   std::unique_ptr<MusSpecificState> mus_state_;
 
   std::unique_ptr<SessionStateDelegate> session_state_delegate_;
 
+  std::unique_ptr<DisplaySynchronizer> display_synchronizer_;
+
   bool added_display_observer_ = false;
   base::ObserverList<WmDisplayObserver> display_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(ShellPortMash);
 };
 
 }  // namespace mus
 }  // namespace ash
 
 #endif  // ASH_MUS_BRIDGE_SHELL_PORT_MASH_H_