Remove unused ash::SHELF_ALIGNMENT_TOP

ash/system/cast/tray_cast.cc

 // Copyright 2015 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/cast/tray_cast.h"
 
 #include "ash/session/session_state_delegate.h"
 #include "ash/shelf/shelf_types.h"
 #include "ash/shell.h"
 #include "ash/system/chromeos/screen_security/screen_tray_item.h"
@@ skipping 342 matching lines @@
 }
 
 CastTrayView::~CastTrayView() {
 }
 
 void CastTrayView::UpdateAlignment(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;
   }
   SetLayoutManager(new views::BoxLayout(layout, 0, 0, 0));
   Layout();
 }
@@ skipping 305 matching lines @@
   is_casting_ = started;
   UpdatePrimaryView();
 }
 
 void TrayCast::UpdateAfterShelfAlignmentChange(ShelfAlignment alignment) {
   if (tray_)
     tray_->UpdateAlignment(alignment);
 }
 
 }  // namespace ash