Remove unused ash::SHELF_ALIGNMENT_TOP

ash/shelf/shelf.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/shelf.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "ash/focus_cycler.h"
@@ skipping 57 matching lines @@
   return shelf_widget ? shelf_widget->shelf() : NULL;
 }
 
 void Shelf::SetAlignment(ShelfAlignment alignment) {
   alignment_ = alignment;
   shelf_view_->OnShelfAlignmentChanged();
   // ShelfLayoutManager will resize the shelf.
 }
 
 bool Shelf::IsHorizontalAlignment() const {
-  return alignment_ == SHELF_ALIGNMENT_BOTTOM ||
-         alignment_ == SHELF_ALIGNMENT_TOP;
+  return alignment_ == SHELF_ALIGNMENT_BOTTOM;
 }
 
 void Shelf::SetAutoHideBehavior(ShelfAutoHideBehavior behavior) {
   shelf_widget_->shelf_layout_manager()->SetAutoHideBehavior(behavior);
 }
 
 ShelfAutoHideBehavior Shelf::GetAutoHideBehavior() const {
   return shelf_widget_->shelf_layout_manager()->auto_hide_behavior();
 }
 
@@ skipping 97 matching lines @@
 
 gfx::Rect Shelf::GetVisibleItemsBoundsInScreen() const {
   return shelf_view_->GetVisibleItemsBoundsInScreen();
 }
 
 app_list::ApplicationDragAndDropHost* Shelf::GetDragAndDropHostForAppList() {
   return shelf_view_;
 }
 
 }  // namespace ash