Move DisplayChangeObserver + tests from ash to ui.

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 21 matching lines @@
 class ActivationClient;
 class FocusClient;
 }
 }
 
 namespace chromeos {
 class AudioA11yController;
 }
 
 namespace display {
+class DisplayChangeObserver;
 class DisplayManager;
 }
 
 namespace gfx {
 class Rect;
 }
 
 namespace ui {
 class DisplayConfigurator;
 class UserActivityDetector;
@@ skipping 14 matching lines @@
 class VisibilityController;
 class WindowModalityController;
 }
 
 namespace ash {
 
 class AcceleratorControllerDelegateAura;
 class AshNativeCursorManager;
 class AutoclickController;
 class BluetoothNotificationController;
-class DisplayChangeObserver;
 class DisplayColorManager;
 class DisplayConfigurationController;
 class DisplayErrorObserver;
 class DragDropController;
 class EventClientImpl;
 class EventTransformationHandler;
 class FirstRunHelper;
 class GPUSupport;
 class HighContrastController;
 class ImmersiveHandlerFactoryAsh;
@@ skipping 415 matching lines @@
       bluetooth_notification_controller_;
   std::unique_ptr<VirtualKeyboardController> virtual_keyboard_controller_;
   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_;
+  std::unique_ptr<display::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_;
 
@@ skipping 21 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_