diff -r 000000000000 -r 6474c204b198 layout/xul/nsIBoxObject.idl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/xul/nsIBoxObject.idl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; 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 "nsISupports.idl"
+
+interface nsIDOMElement;
+
+[scriptable, uuid(ce572460-b0f2-4650-a9e7-c53a99d3b6ad)]
+interface nsIBoxObject : nsISupports
+{
+  readonly attribute nsIDOMElement element;
+
+  readonly attribute long x;
+  readonly attribute long y;
+  readonly attribute long screenX;
+  readonly attribute long screenY;
+  readonly attribute long width;
+  readonly attribute long height;
+
+  nsISupports getPropertyAsSupports(in wstring propertyName);
+  void setPropertyAsSupports(in wstring propertyName, in nsISupports value);
+  wstring getProperty(in wstring propertyName);
+  void setProperty(in wstring propertyName, in wstring propertyValue);
+  void removeProperty(in wstring propertyName);
+  
+  // for stepping through content in the expanded dom with box-ordinal-group order
+  readonly attribute nsIDOMElement parentBox;
+  readonly attribute nsIDOMElement firstChild;
+  readonly attribute nsIDOMElement lastChild;
+  readonly attribute nsIDOMElement nextSibling;
+  readonly attribute nsIDOMElement previousSibling;
+};
+
+%{C++
+nsresult
+NS_NewBoxObject(nsIBoxObject** aResult);
+
+%}