Replace ShelfItemDelegate::GetTitle() with ShelfItem::title.

ash/common/shelf/app_list_shelf_item_delegate.h

Index: ash/common/shelf/app_list_shelf_item_delegate.h
diff --git a/ash/common/shelf/app_list_shelf_item_delegate.h b/ash/common/shelf/app_list_shelf_item_delegate.h
index 38840523999e816e49cfb2bcc76c8021699b1253..82a122d9f0496f9113bed9cc2b6b37bab384f777 100644
--- a/ash/common/shelf/app_list_shelf_item_delegate.h
+++ b/ash/common/shelf/app_list_shelf_item_delegate.h
@@ -15,8 +15,8 @@ class ShelfModel;
 class AppListShelfItemDelegate : public ShelfItemDelegate {
  public:
   // Initializes the app list item in the shelf data model and creates an
-  // AppListShelfItemDelegate which will be owned by |shelf_model|.
-  static void CreateAppListItemAndDelegate(ShelfModel* shelf_model);
+  // AppListShelfItemDelegate which will be owned by |model|.
+  static void CreateAppListItemAndDelegate(ShelfModel* model);
 
   AppListShelfItemDelegate();
   ~AppListShelfItemDelegate() override;
@@ -24,7 +24,6 @@ class AppListShelfItemDelegate : public ShelfItemDelegate {
   // ShelfItemDelegate:
   ShelfItemDelegate::PerformedAction ItemSelected(
       const ui::Event& event) override;
-  base::string16 GetTitle() override;
   ShelfMenuModel* CreateApplicationMenu(int event_flags) override;
   void Close() override;