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

ash/common/shelf/shelf_window_watcher.cc

Index: ash/common/shelf/shelf_window_watcher.cc
diff --git a/ash/common/shelf/shelf_window_watcher.cc b/ash/common/shelf/shelf_window_watcher.cc
index b4087c29f599ce7722de355cdd2e80497d0e747b..50f369969115571868079a582fd69776e3eefa4f 100644
--- a/ash/common/shelf/shelf_window_watcher.cc
+++ b/ash/common/shelf/shelf_window_watcher.cc
@@ -39,6 +39,8 @@ void UpdateShelfItemForWindow(ShelfItem* item, WmWindow* window) {
   if (item->image.isNull())
     item->image = window->GetWindowIcon();
 
+  item->title = window->GetTitle();
+
   // Do not show tooltips for visible attached app panel windows.
   item->shows_tooltip =
       item->type != TYPE_APP_PANEL || !window->IsVisible() ||
@@ -109,6 +111,11 @@ void ShelfWindowWatcher::UserWindowObserver::OnWindowVisibilityChanged(
   window_watcher_->OnUserWindowPropertyChanged(window);
 }
 
+void ShelfWindowWatcher::UserWindowObserver::OnWindowTitleChanged(
+    WmWindow* window) {
+  window_watcher_->OnUserWindowPropertyChanged(window);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 ShelfWindowWatcher::ShelfWindowWatcher(ShelfModel* model)