chromeos: removes mash shadows

ash/mus/shadow_controller.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_MUS_SHADOW_CONTROLLER_H_
-#define ASH_MUS_SHADOW_CONTROLLER_H_
-
-#include "base/macros.h"
-#include "ui/aura/client/focus_change_observer.h"
-#include "ui/aura/env_observer.h"
-#include "ui/aura/window_observer.h"
-
-namespace aura {
-namespace client {
-class FocusClient;
-}
-}
-
-namespace ash {
-namespace mus {
-
-// TODO: use the wm::ShadowController. http://crbug.com/670840.
-class ShadowController : public aura::EnvObserver,
-                         public aura::WindowObserver,
-                         public aura::client::FocusChangeObserver {
- public:
-  ShadowController();
-  ~ShadowController() override;
-
- private:
-  void SetActiveWindow(aura::Window* window);
-  void SetFocusClient(aura::client::FocusClient* focus_client);
-
-  // aura::EnvObserver:
-  void OnWindowInitialized(aura::Window* window) override;
-  void OnActiveFocusClientChanged(aura::client::FocusClient* focus_client,
-                                  aura::Window* window) override;
-
-  // aura::client::FocusChangeObserver:
-  void OnWindowFocused(aura::Window* gained_focus,
-                       aura::Window* lost_focus) override;
-
-  // ui::WindowObserver:
-  void OnWindowDestroying(aura::Window* window) override;
-
-  aura::Window* active_window_ = nullptr;
-  aura::client::FocusClient* active_focus_client_ = nullptr;
-
-  DISALLOW_COPY_AND_ASSIGN(ShadowController);
-};
-
-}  // namespace mus
-}  // namespace ash
-
-#endif  // ASH_MUS_SHADOW_CONTROLLER_H_