diff -r 000000000000 -r 6474c204b198 dom/interfaces/xul/nsIDOMXULRelatedElement.idl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/interfaces/xul/nsIDOMXULRelatedElement.idl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,18 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "domstubs.idl"
+
+[scriptable, uuid(9fbac05a-fb27-470d-8e5f-028b2dc54ad0)]
+interface nsIDOMXULRelatedElement : nsISupports
+{
+  /**
+   * Retrun an element associated with the given element. It's implemented
+   * by container elements having relation between their items. For example,
+   * this interface is implemented by XUL tabs and XUL tabpanels elements
+   * and used to get XUL tab element by linked tab panel and vice versa.
+   */
+  nsIDOMNode getRelatedElement(in nsIDOMNode aElement);
+};