mash: Move SystemTrayDelegate and dependencies to //ash/common

ash/common/system/volume_control_delegate.h

 // Copyright (c) 2012 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_VOLUME_CONTROL_DELEGATE_H_
-#define ASH_VOLUME_CONTROL_DELEGATE_H_
+#ifndef ASH_COMMON_SYSTEM_VOLUME_CONTROL_DELEGATE_H_
+#define ASH_COMMON_SYSTEM_VOLUME_CONTROL_DELEGATE_H_
 
 namespace ui {
 class Accelerator;
 }  // namespace ui
 
 namespace ash {
 
 // Delegate for controlling the volume.
 class VolumeControlDelegate {
  public:
   virtual ~VolumeControlDelegate() {}
 
   virtual void HandleVolumeMute(const ui::Accelerator& accelerator) = 0;
   virtual void HandleVolumeDown(const ui::Accelerator& accelerator) = 0;
   virtual void HandleVolumeUp(const ui::Accelerator& accelerator) = 0;
 };
 
 }  // namespace ash
 
-#endif  // ASH_VOLUME_CONTROL_DELEGATE_H_
+#endif  // ASH_COMMON_SYSTEM_VOLUME_CONTROL_DELEGATE_H_