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

ash/common/test/test_shelf_item_delegate.cc

Index: ash/common/test/test_shelf_item_delegate.cc
diff --git a/ash/common/test/test_shelf_item_delegate.cc b/ash/common/test/test_shelf_item_delegate.cc
index f4ee1124581c538dcbf7465c770bd2156de3c893..a9a6a9681004e63ff2967d0fc846bd5da13c1a12 100644
--- a/ash/common/test/test_shelf_item_delegate.cc
+++ b/ash/common/test/test_shelf_item_delegate.cc
@@ -26,10 +26,6 @@ ShelfItemDelegate::PerformedAction TestShelfItemDelegate::ItemSelected(
   return kNoAction;
 }
 
-base::string16 TestShelfItemDelegate::GetTitle() {
-  return window_ ? window_->GetTitle() : base::string16();
-}
-
 ShelfMenuModel* TestShelfItemDelegate::CreateApplicationMenu(int event_flags) {
   return nullptr;
 }