mash: Support ShelfModel access in Chrome.

chrome/browser/ui/ash/launcher/chrome_launcher_controller_browsertest.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 "chrome/browser/ui/ash/launcher/chrome_launcher_controller.h"
 
 #include <stddef.h>
 
 #include "ash/public/cpp/shelf_item_delegate.h"
 #include "ash/public/cpp/window_properties.h"
@@ skipping 2484 matching lines @@
 
   // Close all windows via the menu item.
   CloseBrowserWindow(browser(), menu1.get(), LauncherContextMenu::MENU_CLOSE);
   EXPECT_EQ(0u, BrowserList::GetInstance()->size());
 
   // Check if "Close" is removed from the context menu.
   std::unique_ptr<LauncherContextMenu> menu2 = CreateBrowserItemContextMenu();
   ASSERT_FALSE(
       IsItemPresentInMenu(menu2.get(), LauncherContextMenu::MENU_CLOSE));
 }
+
+// Chrome's ShelfModel should have AppList and browser items and delegates.
+IN_PROC_BROWSER_TEST_F(ShelfAppBrowserTest, ShelfModelInitialization) {
+  ash::ShelfModel* model = controller_->shelf_model();
+  EXPECT_EQ(2, model->item_count());
+  EXPECT_EQ(ash::kAppListId, model->items()[0].id.app_id);
+  EXPECT_TRUE(model->GetShelfItemDelegate(model->items()[0].id));
+  EXPECT_EQ(extension_misc::kChromeAppId, model->items()[1].id.app_id);
+  EXPECT_TRUE(model->GetShelfItemDelegate(model->items()[1].id));
+}