mash: Cleanup ash shelf application menu code.

ash/shell/window_watcher_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/shell/window_watcher_shelf_item_delegate.h"
 
 #include "ash/shell/window_watcher.h"
 #include "ash/wm/window_util.h"
 #include "ui/aura/window.h"
 
@@ skipping 13 matching lines @@
 ShelfItemDelegate::PerformedAction WindowWatcherShelfItemDelegate::ItemSelected(
     const ui::Event& event) {
   aura::Window* window = watcher_->GetWindowByID(id_);
   if (window->type() == ui::wm::WINDOW_TYPE_PANEL)
     wm::MoveWindowToEventRoot(window, event);
   window->Show();
   wm::ActivateWindow(window);
   return kExistingWindowActivated;
 }
 
-ui::SimpleMenuModel* WindowWatcherShelfItemDelegate::CreateApplicationMenu(
+ShelfApplicationMenuItems WindowWatcherShelfItemDelegate::GetAppMenuItems(
     int event_flags) {
-  return nullptr;
+  return ShelfApplicationMenuItems();

[James Cook, 2017/02/06 17:30:21]

Given that the type of ShelfApplicationMenuItems isn't available at this line, I
would add a comment like "No items" or "Empty list".

(This is why I don't like "using" for lists of things, and why I prefer FooList
to Foos. However, both are used extensively in the code base, so I'm OK with
continuing to use SAMIs).

[msw, 2017/02/07 09:12:01]

I added comments, renamed to ShelfAppMenuItemList, and I may use vectors of mojo
structs without a 'using' alias in the near future.

 }
 
 void WindowWatcherShelfItemDelegate::Close() {}
 
 }  // namespace shell
 }  // namespace ash