Fork a subset of ash/shelf for use in mash.

mash/shelf/shelf_constants.cc

 // Copyright 2013 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.
 
-#include "ash/shelf/shelf_constants.h"
+#include "mash/shelf/shelf_constants.h"
 
-namespace ash {
+namespace mash {
+namespace shelf {
 
 const int kShelfBackgroundAlpha = 204;
 const int kInvalidImageResourceID = -1;
+const int kInvalidShelfID = 0;
 const int kShelfSize = 47;
 const int kShelfButtonSpacing = 10;
 const int kShelfButtonSize = 44;
 const int kTimeToSwitchBackgroundMs = 1000;
 
-}  // namespace ash
+}  // namespace shelf
+}  // namespace mash