mash: Move ShelfModel* to ash/public/cpp.

ash/shelf/app_list_shelf_item_delegate.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/app_list_shelf_item_delegate.h"
 
 #include <utility>
 
-#include "ash/shelf/shelf_model.h"
+#include "ash/public/cpp/shelf_model.h"
 #include "ash/shell.h"
 
 namespace ash {
 
 AppListShelfItemDelegate::AppListShelfItemDelegate()
     : ShelfItemDelegate(ShelfID(kAppListId)) {}
 
 AppListShelfItemDelegate::~AppListShelfItemDelegate() {}
 
 void AppListShelfItemDelegate::ItemSelected(std::unique_ptr<ui::Event> event,
                                             int64_t display_id,
                                             ShelfLaunchSource source,
                                             ItemSelectedCallback callback) {
   Shell::Get()->ToggleAppList();
   std::move(callback).Run(SHELF_ACTION_APP_LIST_SHOWN, base::nullopt);
 }
 
 void AppListShelfItemDelegate::ExecuteCommand(uint32_t command_id,
                                               int32_t event_flags) {
   // This delegate does not support showing an application menu.
   NOTIMPLEMENTED();
 }
 
 void AppListShelfItemDelegate::Close() {}
 
 }  // namespace ash