chromeos: Move files in //ash/common to //ash, part 2

ash/common/wm/overview/cleanup_animation_observer.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/common/wm/overview/cleanup_animation_observer.h"
-
-#include "ui/views/widget/widget.h"
-
-namespace ash {
-
-CleanupAnimationObserver::CleanupAnimationObserver(
-    std::unique_ptr<views::Widget> widget)
-    : widget_(std::move(widget)), owner_(nullptr) {
-  DCHECK(widget_);
-}
-
-CleanupAnimationObserver::~CleanupAnimationObserver() {}
-
-void CleanupAnimationObserver::OnImplicitAnimationsCompleted() {
-  // |widget_| may get reset if Shutdown() is called prior to this method.
-  if (!widget_)
-    return;
-  if (owner_) {
-    owner_->RemoveAndDestroyAnimationObserver(this);
-    return;
-  }
-  delete this;
-}
-
-void CleanupAnimationObserver::SetOwner(WindowSelectorDelegate* owner) {
-  owner_ = owner;
-}
-
-void CleanupAnimationObserver::Shutdown() {
-  widget_.reset();
-  owner_ = nullptr;
-}
-
-}  // namespace ash