After uninstall, remove last item in Launcher folder

ui/app_list/app_list_model.h

Index: ui/app_list/app_list_model.h
diff --git a/ui/app_list/app_list_model.h b/ui/app_list/app_list_model.h
index 6c61e71d68ebbed73c6a0c9c23dd195ef2ad5cdf..0bfd790dceacb60258669f97ad4d61de782f9902 100644
--- a/ui/app_list/app_list_model.h
+++ b/ui/app_list/app_list_model.h
@@ -125,6 +125,10 @@ class APP_LIST_EXPORT AppListModel : public AppListItemListObserver {
   // appropriate folder.
   void DeleteItem(const std::string& id);
 
+  // Wrapper around DeleteItem() which will also clean up if its parent folder
+  // has a single child left.
+  void DeleteUninstalledItem(const std::string& id);
+
   // Call OnExtensionPreferenceChanged() for all items in the model.
   void NotifyExtensionPreferenceChanged();