Move shadow code to views\corewm

ash/wm/shadow_types.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_WM_SHADOW_TYPES_H_
-#define ASH_WM_SHADOW_TYPES_H_
-
-#include "ash/ash_export.h"
-
-namespace aura {
-class Window;
-}
-
-namespace ash {
-namespace internal {
-
-// Different types of drop shadows that can be drawn under a window by the
-// shell.  Used as a value for the kShadowTypeKey property.
-enum ShadowType {
-  // Starts at 0 due to the cast in GetShadowType().
-  SHADOW_TYPE_NONE = 0,
-  SHADOW_TYPE_RECTANGULAR,
-};
-
-ASH_EXPORT void SetShadowType(aura::Window* window, ShadowType shadow_type);
-ASH_EXPORT ShadowType GetShadowType(aura::Window* window);
-
-}  // namespace internal
-}  // namespace ash
-
-#endif  // ASH_WM_SHADOW_TYPES_H_