diff -r 000000000000 -r 6474c204b198 dom/interfaces/base/nsIDOMClientRect.idl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/interfaces/base/nsIDOMClientRect.idl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,17 @@
+/* -*- 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(B2F824C4-D9D3-499B-8D3B-45C8245497C6)]
+interface nsIDOMClientRect : nsISupports
+{
+  readonly attribute float left;
+  readonly attribute float top;
+  readonly attribute float right;
+  readonly attribute float bottom;
+  readonly attribute float width;
+  readonly attribute float height;
+};