mash: Cleanup ash shelf application menu code.

ash/shell/window_watcher_shelf_item_delegate.cc

Index: ash/shell/window_watcher_shelf_item_delegate.cc
diff --git a/ash/shell/window_watcher_shelf_item_delegate.cc b/ash/shell/window_watcher_shelf_item_delegate.cc
index cfceb3c32b56b46eb32805162112861120812e86..502586eaabf63a6fc9a1760aff898d0cfe6d6965 100644
--- a/ash/shell/window_watcher_shelf_item_delegate.cc
+++ b/ash/shell/window_watcher_shelf_item_delegate.cc
@@ -31,9 +31,9 @@ ShelfItemDelegate::PerformedAction WindowWatcherShelfItemDelegate::ItemSelected(
   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() {}