mash: Use mojo for ShelfItemDelegate and [app] MenuItem.

ash/common/shelf/shelf_window_watcher_item_delegate.h

Index: ash/common/shelf/shelf_window_watcher_item_delegate.h
diff --git a/ash/common/shelf/shelf_window_watcher_item_delegate.h b/ash/common/shelf/shelf_window_watcher_item_delegate.h
index fd61f439ff19a73f2d61a3c696b82fded94c40bc..3a4fe270e99382a400183038541657fd77c6c40a 100644
--- a/ash/common/shelf/shelf_window_watcher_item_delegate.h
+++ b/ash/common/shelf/shelf_window_watcher_item_delegate.h
@@ -21,12 +21,11 @@ class ShelfWindowWatcherItemDelegate : public ShelfItemDelegate {
 
  private:
   // ShelfItemDelegate overrides:
-  ShelfAction ItemSelected(ui::EventType event_type,
-                           int event_flags,
-                           int64_t display_id,
-                           ShelfLaunchSource source) override;
-  ShelfAppMenuItemList GetAppMenuItems(int event_flags) override;
-  void ExecuteCommand(uint32_t command_id, int event_flags) override;
+  void ItemSelected(std::unique_ptr<ui::Event> event,
+                    int64_t display_id,
+                    ShelfLaunchSource source,
+                    const ItemSelectedCallback& callback) override;
+  void ExecuteCommand(uint32_t command_id, int32_t event_flags) override;
   void Close() override;
 
   ShelfID id_;