[ash] Cleanup of ScopedOverviewAnimationSettings

ash/wm/overview/scoped_overview_animation_settings_factory_aura.cc

-// 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.
-
-#include "ash/wm/overview/scoped_overview_animation_settings_factory_aura.h"
-
-#include "ash/wm/overview/scoped_overview_animation_settings_aura.h"
-#include "base/memory/ptr_util.h"
-#include "ui/aura/window.h"
-
-namespace ash {
-
-ScopedOverviewAnimationSettingsFactoryAura::
-    ScopedOverviewAnimationSettingsFactoryAura() {}
-
-ScopedOverviewAnimationSettingsFactoryAura::
-    ~ScopedOverviewAnimationSettingsFactoryAura() {}
-
-std::unique_ptr<ScopedOverviewAnimationSettings>
-ScopedOverviewAnimationSettingsFactoryAura::CreateOverviewAnimationSettings(
-    OverviewAnimationType animation_type,
-    aura::Window* window) {
-  return base::MakeUnique<ScopedOverviewAnimationSettingsAura>(animation_type,
-                                                               window);
-}
-
-}  // namespace ash