After uninstall, remove last item in Launcher folder

ui/app_list/app_list_model.cc

Index: ui/app_list/app_list_model.cc
diff --git a/ui/app_list/app_list_model.cc b/ui/app_list/app_list_model.cc
index 0a8e0cd33bfc5b8b006eb65fd62d4dbaf375cb41..48394478d48db0605cafddc3bcadcc3e82c3acdf 100644
--- a/ui/app_list/app_list_model.cc
+++ b/ui/app_list/app_list_model.cc
@@ -280,6 +280,22 @@ void AppListModel::DeleteItem(const std::string& id) {
   FOR_EACH_OBSERVER(AppListModelObserver, observers_, OnAppListItemDeleted());
 }
 
+void AppListModel::DeleteUninstalledItem(const std::string& id) {
+  AppListItem* item = FindItem(id);
+  if (!item)
+    return;
+  const std::string folder_id = item->folder_id();
+  DeleteItem(id);
+
+  // crbug.com/368111: Upon uninstall of 2nd-to-last folder item, reparent last
+  // item to top; this will remove the folder.
+  AppListFolderItem* folder = FindFolderItem(folder_id);
+  if (folder && folder->ChildItemCount() == 1u) {
+    AppListItem* last_item = folder->item_list()->item_at(0);
+    MoveItemToFolderAt(last_item, "", folder->position());
+  }
+}
+
 void AppListModel::NotifyExtensionPreferenceChanged() {
   for (size_t i = 0; i < top_level_item_list_->item_count(); ++i)
     top_level_item_list_->item_at(i)->OnExtensionPreferenceChanged();