Animate the OverviewButtonTray

ash/system/status_area_widget_delegate.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_SYSTEM_STATUS_AREA_WIDGET_DELEGATE_H_
 #define ASH_SYSTEM_STATUS_AREA_WIDGET_DELEGATE_H_
 
 #include "ash/ash_export.h"
 #include "ash/shelf/shelf_types.h"
 #include "ash/wm/gestures/shelf_gesture_handler.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/views/accessible_pane_view.h"
 #include "ui/views/widget/widget_delegate.h"
 
+namespace ui {
+class Layer;
+class ScopedLayerAnimationSettings;
+}  // namespace ui
+
 namespace ash {
 class FocusCycler;
 
 class ASH_EXPORT StatusAreaWidgetDelegate : public views::AccessiblePaneView,
                                             public views::WidgetDelegate {
  public:
   StatusAreaWidgetDelegate();
   virtual ~StatusAreaWidgetDelegate();
 
   // Add a tray view to the widget (e.g. system tray, web notifications).
@@ skipping 22 matching lines @@
   virtual void DeleteDelegate() OVERRIDE;
 
  protected:
   // Overridden from views::View:
   virtual void ChildPreferredSizeChanged(views::View* child) OVERRIDE;
   virtual void ChildVisibilityChanged(views::View* child) OVERRIDE;
 
  private:
   void UpdateWidgetSize();
 
+  ui::ScopedLayerAnimationSettings* SetupAnimationForLayer(ui::Layer* layer);
+
   const FocusCycler* focus_cycler_for_testing_;
   ShelfAlignment alignment_;
 
   ShelfGestureHandler gesture_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(StatusAreaWidgetDelegate);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_STATUS_AREA_WIDGET_DELEGATE_H_