ash: Cleanup class/struct forward declarations

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>
 
 #include "ash/ash_export.h"
 #include "ash/metrics/user_metrics_recorder.h"
 #include "ash/public/cpp/shelf_types.h"
 #include "ash/wm/cursor_manager_chromeos.h"
 #include "ash/wm/system_modal_container_event_filter_delegate.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "ui/aura/window.h"
 #include "ui/display/screen.h"
 #include "ui/events/event_target.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/wm/core/cursor_manager.h"
 
 namespace aura {
-class EventFilter;
 class RootWindow;
 class Window;
 namespace client {
 class ActivationClient;
 class FocusClient;
 }
 }
 
 namespace chromeos {
 class AudioA11yController;
 }
 
 namespace display {
 class DisplayManager;
 }
 
 namespace gfx {
-class ImageSkia;
 class Rect;
 }
 
 namespace ui {
 class DisplayConfigurator;
-class Layer;
 class UserActivityDetector;
 class UserActivityPowerManagerNotifier;
 }
 namespace views {
 class NonClientFrameView;
 class Widget;
 namespace corewm {
 class TooltipController;
 }
 }
@@ skipping 11 matching lines @@
 class AcceleratorControllerDelegateAura;
 class AshNativeCursorManager;
 class AutoclickController;
 class BluetoothNotificationController;
 class DisplayChangeObserver;
 class DisplayColorManager;
 class DisplayConfigurationController;
 class DisplayErrorObserver;
 class DragDropController;
 class EventClientImpl;
-class EventRewriterEventFilter;
 class EventTransformationHandler;
 class FirstRunHelper;
 class GPUSupport;
 class HighContrastController;
 class ImmersiveHandlerFactoryAsh;
 class LaserPointerController;
 class LinkHandlerModelFactory;
 class LockStateController;
 enum class LoginStatus;
 class MagnificationController;
 class MouseCursorEventFilter;
 class OverlayEventFilter;
 class PartialMagnificationController;
 class PowerButtonController;
 class PowerEventObserver;
 class ProjectingObserver;
 class ResizeShadowController;
 class ResolutionNotificationController;
 class RootWindowController;
 class ScopedOverviewAnimationSettingsFactoryAura;
-class ScreenAsh;
 class ScreenOrientationController;
 class ScreenshotController;
 class ScreenPinningController;
 class ScreenPositionController;
 class SessionStateDelegate;
 class ShellDelegate;
 struct ShellInitParams;
-class SlowAnimationEventFilter;
-class StatusAreaWidget;
 class StickyKeysController;
 class SystemGestureEventFilter;
 class SystemModalContainerEventFilter;
 class SystemTray;
 class ToplevelWindowEventHandler;
 class TouchTransformerController;
-class TouchObserverHUD;
 class ScreenLayoutObserver;
 class VirtualKeyboardController;
 class VideoActivityNotifier;
 class VideoDetector;
 class WebNotificationTray;
 class WindowPositioner;
 class WindowTreeHostManager;
 class WmShellAura;
 class WmWindow;
 
@@ skipping 415 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_