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

ash/common/shelf/shelf_window_watcher_item_delegate.cc

Index: ash/common/shelf/shelf_window_watcher_item_delegate.cc
diff --git a/ash/common/shelf/shelf_window_watcher_item_delegate.cc b/ash/common/shelf/shelf_window_watcher_item_delegate.cc
index 0738ce567c8cad95f41962068edacc6638cf1faf..303ef6a0841733085aead5007dbedf9d3ef66069 100644
--- a/ash/common/shelf/shelf_window_watcher_item_delegate.cc
+++ b/ash/common/shelf/shelf_window_watcher_item_delegate.cc
@@ -55,10 +55,6 @@ ShelfItemDelegate::PerformedAction ShelfWindowWatcherItemDelegate::ItemSelected(
   return kExistingWindowActivated;
 }
 
-base::string16 ShelfWindowWatcherItemDelegate::GetTitle() {
-  return window_->GetTitle();
-}
-
 ShelfMenuModel* ShelfWindowWatcherItemDelegate::CreateApplicationMenu(
     int event_flags) {
   return nullptr;