Update shelf spacing in Chrome OS according to the MD specs

ash/shelf/overflow_bubble_view.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/overflow_bubble_view.h"
 
 #include <algorithm>
 
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf.h"
@@ skipping 158 matching lines @@
 }
 
 gfx::Rect OverflowBubbleView::GetBubbleBounds() {
   views::BubbleBorder* border = GetBubbleFrameView()->bubble_border();
   gfx::Insets bubble_insets = border->GetInsets();
 
   const int border_size =
       views::BubbleBorder::is_arrow_on_horizontal(arrow()) ?
       bubble_insets.left() : bubble_insets.top();
   const int arrow_offset = border_size + kPadding + kShelfViewLeadingInset +
-      kShelfSize / 2;
+                           GetShelfLayoutConstant(SHELF_SIZE) / 2;
 
   const gfx::Size content_size = GetPreferredSize();
   border->set_arrow_offset(arrow_offset);
 
   const gfx::Rect anchor_rect = GetAnchorRect();
   gfx::Rect bubble_rect = GetBubbleFrameView()->GetUpdatedWindowBounds(
       anchor_rect,
       content_size,
       false);
 
@@ skipping 19 matching lines @@
 
     bubble_rect.Offset(0, offset);
     border->set_arrow_offset(anchor_rect.CenterPoint().y() - bubble_rect.y());
   }
 
   GetBubbleFrameView()->SchedulePaint();
   return bubble_rect;
 }
 
 }  // namespace ash