Move Screen, its impls, DisplayObserver and DisplayChangeNotifier to ui/display

ui/gfx/display_change_notifier.h

-// Copyright 2014 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 UI_GFX_DISPLAY_CHANGE_NOTIFIER_H_
-#define UI_GFX_DISPLAY_CHANGE_NOTIFIER_H_
-
-#include <vector>
-
-#include "base/macros.h"
-#include "base/observer_list.h"
-#include "ui/gfx/gfx_export.h"
-
-namespace gfx {
-
-class Display;
-class DisplayObserver;
-
-// DisplayChangeNotifier is a class implementing the handling of DisplayObserver
-// notification for Screen.
-class GFX_EXPORT DisplayChangeNotifier {
- public:
-  DisplayChangeNotifier();
-  ~DisplayChangeNotifier();
-
-  void AddObserver(DisplayObserver* observer);
-
-  void RemoveObserver(DisplayObserver* observer);
-
-  void NotifyDisplaysChanged(const std::vector<Display>& old_displays,
-                             const std::vector<Display>& new_displays);
-
- private:
-  // The observers that need to be notified when a display is modified, added
-  // or removed.
-  base::ObserverList<DisplayObserver> observer_list_;
-
-  DISALLOW_COPY_AND_ASSIGN(DisplayChangeNotifier);
-};
-
-} // namespace gfx
-
-#endif // UI_GFX_DISPLAY_CHANGE_NOTIFIER_H_
-