chromeos: Move files in //ash/common to //ash

ash/common/wm/window_dimmer.h

-// Copyright 2015 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_COMMON_WINDOW_DIMMER_H_
-#define ASH_COMMON_WINDOW_DIMMER_H_
-
-#include "ash/ash_export.h"
-#include "base/macros.h"
-#include "ui/aura/window_observer.h"
-
-namespace ash {
-
-class WmWindow;
-
-// WindowDimmer creates a window whose opacity is animated by way of
-// SetDimOpacity() and whose size matches that of its parent. WindowDimmer is
-// intended to be used in cases where a certain set of windows need to appear
-// partially obscured. This is achieved by creating WindowDimmer, setting the
-// opacity, and then stacking window() above the windows that are to appear
-// obscured. The window created by WindowDimmer is owned by the parent, but also
-// deleted if WindowDimmer is deleted. It is expected that WindowDimmer is
-// deleted when the parent window is deleted (such as happens with
-// WmWindowUserData).
-class ASH_EXPORT WindowDimmer : public aura::WindowObserver {
- public:
-  // Creates a new WindowDimmer. The window() created by WindowDimmer is added
-  // to |parent| and stacked above all other child windows.
-  explicit WindowDimmer(WmWindow* parent);
-  ~WindowDimmer() override;
-
-  void SetDimOpacity(float target_opacity);
-
-  WmWindow* parent() { return parent_; }
-  WmWindow* window() { return window_; }
-
-  // NOTE: WindowDimmer is an observer for both |parent_| and |window_|.
-  // aura::WindowObserver:
-  void OnWindowBoundsChanged(aura::Window* window,
-                             const gfx::Rect& old_bounds,
-                             const gfx::Rect& new_bounds) override;
-  void OnWindowDestroying(aura::Window* window) override;
-  void OnWindowHierarchyChanging(const HierarchyChangeParams& params) override;
-
- private:
-  WmWindow* parent_;
-  WmWindow* window_;
-
-  DISALLOW_COPY_AND_ASSIGN(WindowDimmer);
-};
-
-}  // namespace ash
-
-#endif  // ASH_COMMON_WINDOW_DIMMER_H_