[ash] Cleanup of ScopedOverviewAnimationSettings

ash/wm/overview/scoped_overview_animation_settings_aura.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_WM_OVERVIEW_SCOPED_OVERVIEW_ANIMATION_SETTINGS_AURA_H_
-#define ASH_WM_OVERVIEW_SCOPED_OVERVIEW_ANIMATION_SETTINGS_AURA_H_
-
-#include <memory>
-
-#include "ash/wm/overview/overview_animation_type.h"
-#include "ash/wm/overview/scoped_overview_animation_settings.h"
-#include "base/macros.h"
-
-namespace aura {
-class Window;
-}  // namespace aura
-
-namespace ui {
-class ScopedLayerAnimationSettings;
-}  // namespace ui
-
-namespace ash {
-
-// ScopedOverviewAnimationSettingsfor aura.
-class ScopedOverviewAnimationSettingsAura
-    : public ScopedOverviewAnimationSettings {
- public:
-  ScopedOverviewAnimationSettingsAura(OverviewAnimationType animation_type,
-                                      aura::Window* window);
-  ~ScopedOverviewAnimationSettingsAura() override;
-  void AddObserver(ui::ImplicitAnimationObserver* observer) override;
-
- private:
-  // The managed animation settings.
-  std::unique_ptr<ui::ScopedLayerAnimationSettings> animation_settings_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScopedOverviewAnimationSettingsAura);
-};
-
-}  // namespace ash
-
-#endif  // ASH_WM_OVERVIEW_SCOPED_OVERVIEW_ANIMATION_SETTINGS_AURA_H_