mash: Move shelf model and item classes to ash/common/shelf

ash/shell/window_watcher.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/shell/window_watcher.h"
 
 #include <utility>
 
+#include "ash/common/shelf/shelf_item_delegate_manager.h"
+#include "ash/common/shelf/shelf_model.h"
 #include "ash/common/shell_window_ids.h"
 #include "ash/display/window_tree_host_manager.h"
 #include "ash/shelf/shelf.h"
-#include "ash/shelf/shelf_item_delegate_manager.h"
-#include "ash/shelf/shelf_model.h"
 #include "ash/shelf/shelf_util.h"
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shell.h"
 #include "ash/shell/window_watcher_shelf_item_delegate.h"
 #include "ash/wm/window_util.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/display/display.h"
 
 namespace ash {
@@ skipping 124 matching lines @@
 void WindowWatcher::OnDisplayRemoved(const display::Display& old_display) {
   // All windows in the display has already been removed, so no need to
   // remove observers.
 }
 
 void WindowWatcher::OnDisplayMetricsChanged(const display::Display&, uint32_t) {
 }
 
 }  // namespace shell
 }  // namespace ash