Revert "chromeos: Move files in //ash/common to //ash, part 3"

ash/common/wallpaper/wallpaper_controller_observer.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_WALLPAPER_WALLPAPER_CONTROLLER_OBSERVER_H_
-#define ASH_WALLPAPER_WALLPAPER_CONTROLLER_OBSERVER_H_
+#ifndef ASH_COMMON_WALLPAPER_WALLPAPER_CONTROLLER_OBSERVER_H_
+#define ASH_COMMON_WALLPAPER_WALLPAPER_CONTROLLER_OBSERVER_H_
 
 #include "ash/ash_export.h"
 
 namespace ash {
 
 class ASH_EXPORT WallpaperControllerObserver {
  public:
   // Invoked when the wallpaper data is changed.
   virtual void OnWallpaperDataChanged() = 0;
 
   // Invoked when the colors extracted from the current wallpaper change. May
   // be called as a side effect of changing the wallpaper on the
   // WallpaperController, e.g. WallpaperController::SetWallpaperImage().
   virtual void OnWallpaperColorsChanged() {}
 
  protected:
   virtual ~WallpaperControllerObserver() {}
 };
 
 }  // namespace ash
 
-#endif  // ASH_WALLPAPER_WALLPAPER_CONTROLLER_OBSERVER_H_
+#endif  // ASH_COMMON_WALLPAPER_WALLPAPER_CONTROLLER_OBSERVER_H_