Replace IDR window property use with gfx::ImageSkia icons.

ash/common/shelf/shelf_constants.h

 // 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.
 
 #ifndef ASH_COMMON_SHELF_SHELF_CONSTANTS_H_
 #define ASH_COMMON_SHELF_SHELF_CONSTANTS_H_
 
 #include "ash/ash_export.h"
 #include "third_party/skia/include/core/SkColor.h"
 
@@ skipping 10 matching lines @@
   // Size of the space between buttons on the shelf.
   SHELF_BUTTON_SPACING,
 
   // Size allocated for each app button on the shelf.
   SHELF_BUTTON_SIZE,
 
   // Insets allocated for shelf when it is auto hidden.
   SHELF_INSETS_FOR_AUTO_HIDE
 };
 
-// Invalid image resource id used for shelf items.
-const int kInvalidImageResourceID = -1;
-
 // We reserve a small area on the edge of the workspace area to ensure that
 // the resize handle at the edge of the window can be hit.
 extern const int kWorkspaceAreaVisibleInset;
 
 // When autohidden we extend the touch hit target onto the screen so that the
 // user can drag the shelf out.
 extern const int kWorkspaceAreaAutoHideInset;
 
 // Size of the shelf when auto-hidden.
 ASH_EXPORT extern const int kShelfAutoHideSize;
@@ skipping 38 matching lines @@
 extern const int kAppListButtonRadius;
 
 // The direction of the focus cycling.
 enum CycleDirection { CYCLE_FORWARD, CYCLE_BACKWARD };
 
 ASH_EXPORT int GetShelfConstant(ShelfConstant shelf_constant);
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SHELF_SHELF_CONSTANTS_H_