Update shelf spacing in Chrome OS according to the MD specs

ash/test/shelf_view_test_api.cc

 // 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.
 
 #include "ash/test/shelf_view_test_api.h"
 
 #include "ash/shelf/overflow_button.h"
 #include "ash/shelf/shelf_button.h"
 #include "ash/shelf/shelf_constants.h"
 #include "ash/shelf/shelf_model.h"
@@ skipping 93 matching lines @@
 
 ShelfTooltipManager* ShelfViewTestAPI::tooltip_manager() {
   return &shelf_view_->tooltip_;
 }
 
 gfx::Size ShelfViewTestAPI::GetPreferredSize() {
   return shelf_view_->GetPreferredSize();
 }
 
 int ShelfViewTestAPI::GetButtonSize() {
-  return kShelfButtonSize;
+  return GetShelfLayoutConstant(SHELF_BUTTON_SIZE);
 }
 
 int ShelfViewTestAPI::GetButtonSpacing() {
-  return kShelfButtonSpacing;
+  return GetShelfLayoutConstant(SHELF_BUTTON_SPACING);
 }
 
 void ShelfViewTestAPI::ButtonPressed(views::Button* sender,
                                      const ui::Event& event) {
   return shelf_view_->ButtonPressed(sender, event);
 }
 
 bool ShelfViewTestAPI::SameDragType(ShelfItemType typea,
                                     ShelfItemType typeb) const {
   return shelf_view_->SameDragType(typea, typeb);
@@ skipping 15 matching lines @@
     return shelf_view_->dragged_off_from_overflow_to_shelf_;
 }
 
 ShelfButtonPressedMetricTracker*
 ShelfViewTestAPI::shelf_button_pressed_metric_tracker() {
   return &(shelf_view_->shelf_button_pressed_metric_tracker_);
 }
 
 }  // namespace test
 }  // namespace ash