mash: Move LauncherItemController to ash, rename ShelfItemDelegate.

ash/public/cpp/shelf_item_delegate.cc

+// Copyright 2017 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/public/cpp/shelf_item_delegate.h"
+
+namespace ash {
+
+ShelfItemDelegate::ShelfItemDelegate(const ash::AppLaunchId& app_launch_id)
+    : app_launch_id_(app_launch_id),
+      shelf_id_(kInvalidShelfID),
+      image_set_by_controller_(false) {}
+
+ShelfItemDelegate::~ShelfItemDelegate() {}
+
+MenuItemList ShelfItemDelegate::GetAppMenuItems(int event_flags) {
+  return MenuItemList();
+}
+
+AppWindowLauncherItemController*
+ShelfItemDelegate::AsAppWindowLauncherItemController() {
+  return nullptr;
+}
+
+}  // namespace ash