mash: Remove shelf app menu item objects.

ash/common/shelf/shelf_window_watcher_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/common/shelf/shelf_window_watcher_item_delegate.h"
 
 #include "ash/common/shelf/shelf_controller.h"
 #include "ash/common/shelf/shelf_model.h"
 #include "ash/common/wm/window_state.h"
 #include "ash/common/wm_shell.h"
@@ skipping 47 matching lines @@
   window_->Activate();
   return SHELF_ACTION_WINDOW_ACTIVATED;
 }
 
 ShelfAppMenuItemList ShelfWindowWatcherItemDelegate::GetAppMenuItems(
     int event_flags) {
   // Return an empty item list to avoid showing an application menu.
   return ShelfAppMenuItemList();
 }
 
+void ShelfWindowWatcherItemDelegate::ExecuteCommand(uint32_t command_id,
+                                                    int event_flags) {
+  // This delegate does not support showing an application menu.
+  NOTIMPLEMENTED();
+}
+
 void ShelfWindowWatcherItemDelegate::Close() {
   window_->CloseWidget();
 }
 
 }  // namespace ash