Remove DisplayChangeObserver ash dependencies.

ash/shell.h

 // Copyright (c) 2012 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_SHELL_H_
 #define ASH_SHELL_H_
 
 #include <memory>
 #include <utility>
 #include <vector>
@@ skipping 93 matching lines @@
 class RootWindowController;
 class ScopedOverviewAnimationSettingsFactoryAura;
 class ScreenAsh;
 class ScreenOrientationController;
 class ScreenshotController;
 class ScreenPinningController;
 class ScreenPositionController;
 class SessionStateDelegate;
 class ShellDelegate;
 struct ShellInitParams;
+class ShutdownObserver;
 class SlowAnimationEventFilter;
 class StatusAreaWidget;
 class StickyKeysController;
 class SystemGestureEventFilter;
 class SystemModalContainerEventFilter;
 class SystemTray;
 class ToplevelWindowEventHandler;
 class TouchTransformerController;
 class TouchObserverHUD;
 class ScreenLayoutObserver;
@@ skipping 387 matching lines @@
   std::unique_ptr<chromeos::AudioA11yController> audio_a11y_controller_;
   // Controls video output device state.
   std::unique_ptr<ui::DisplayConfigurator> display_configurator_;
   std::unique_ptr<DisplayColorManager> display_color_manager_;
   std::unique_ptr<DisplayErrorObserver> display_error_observer_;
   std::unique_ptr<ProjectingObserver> projecting_observer_;
 
   // Listens for output changes and updates the display manager.
   std::unique_ptr<DisplayChangeObserver> display_change_observer_;
 
+  // Listens for shutdown and updates DisplayConfigurator.
+  std::unique_ptr<ShutdownObserver> shutdown_observer_;
+
   // Implements content::ScreenOrientationController for ChromeOS
   std::unique_ptr<ScreenOrientationController> screen_orientation_controller_;
   std::unique_ptr<ScreenLayoutObserver> screen_layout_observer_;
 
   std::unique_ptr<TouchTransformerController> touch_transformer_controller_;
 
   std::unique_ptr<ui::EventHandler> magnifier_key_scroll_handler_;
   std::unique_ptr<ui::EventHandler> speech_feedback_handler_;
   std::unique_ptr<LaserPointerController> laser_pointer_controller_;
   std::unique_ptr<PartialMagnificationController>
@@ skipping 17 matching lines @@
   std::unique_ptr<GPUSupport> gpu_support_;
 
   std::unique_ptr<ImmersiveHandlerFactoryAsh> immersive_handler_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_H_