Rename gfx::Display/Screen to display::Display/Screen in ash

ash/system/chromeos/audio/tray_audio_chromeos.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 ASH_SYSTEM_CHROMEOS_AUDIO_TRAY_AUDIO_CHROMEOS_H_
 #define ASH_SYSTEM_CHROMEOS_AUDIO_TRAY_AUDIO_CHROMEOS_H_
 
 #include <stdint.h>
 
 #include "ash/ash_export.h"
@@ skipping 15 matching lines @@
 
  protected:
   // Overridden from TrayAudio
   void Update() override;
 
  private:
   // Overridden from SystemTrayItem.
   views::View* CreateDetailedView(user::LoginStatus status) override;
   void DestroyDetailedView() override;
 
-  // Overridden from gfx::DisplayObserver.
-  void OnDisplayAdded(const gfx::Display& new_display) override;
-  void OnDisplayRemoved(const gfx::Display& old_display) override;
-  void OnDisplayMetricsChanged(const gfx::Display& display,
+  // Overridden from display::DisplayObserver.
+  void OnDisplayAdded(const display::Display& new_display) override;
+  void OnDisplayRemoved(const display::Display& old_display) override;
+  void OnDisplayMetricsChanged(const display::Display& display,
                                uint32_t changed_metrics) override;
 
   // Overriden from chromeos::PowerManagerClient::Observer.
   void SuspendDone(const base::TimeDelta& sleep_duration) override;
 
   tray::AudioDetailedView* audio_detail_view_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayAudioChromeOs);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_CHROMEOS_AUDIO_TRAY_AUDIO_CHROMEOS_H_