ash: Cleanup class/struct forward declarations

ash/screen_util.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_SCREEN_UTIL_H_
 #define ASH_SCREEN_UTIL_H_
 
 #include "ash/ash_export.h"
 #include "base/macros.h"
 
 namespace aura {
 class Window;
 }
 
-namespace display {
-class Display;
-}
-
 namespace gfx {
 class Rect;
-class Point;
 }
 
 namespace ash {
 
 class ASH_EXPORT ScreenUtil {
  public:
   // Returns the bounds for maximized windows in parent coordinates.
   // Maximized windows trigger auto-hiding the shelf.
   static gfx::Rect GetMaximizedWindowBoundsInParent(aura::Window* window);
 
@@ skipping 16 matching lines @@
  private:
   ScreenUtil() {}
   ~ScreenUtil() {}
 
   DISALLOW_COPY_AND_ASSIGN(ScreenUtil);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SCREEN_UTIL_H_