Remove unused ash::SHELF_ALIGNMENT_TOP

ash/system/tray/tray_image_item.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/system/tray/tray_image_item.h"
 
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/tray_item_view.h"
 #include "ash/system/tray/tray_utils.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 58 matching lines @@
 }
 
 void TrayImageItem::DestroyDetailedView() {
 }
 
 void TrayImageItem::SetItemAlignment(ShelfAlignment alignment) {
   // Center the item dependent on the orientation of the shelf.
   views::BoxLayout::Orientation layout = views::BoxLayout::kHorizontal;
   switch (alignment) {
     case ash::SHELF_ALIGNMENT_BOTTOM:
-    case ash::SHELF_ALIGNMENT_TOP:
       layout = views::BoxLayout::kHorizontal;
       break;
     case ash::SHELF_ALIGNMENT_LEFT:
     case ash::SHELF_ALIGNMENT_RIGHT:
       layout = views::BoxLayout::kVertical;
       break;
   }
   tray_view_->SetLayoutManager(new views::BoxLayout(layout, 0, 0, 0));
   tray_view_->Layout();
 }
 
 }  // namespace ash