diff -r 000000000000 -r 6474c204b198 dom/webidl/MessageChannel.webidl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/webidl/MessageChannel.webidl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,14 @@
+/* -*- 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/.
+ *
+ * For more information on this interface, please see
+ * http://www.whatwg.org/specs/web-apps/current-work/#channel-messaging
+ */
+
+[Constructor, Pref="dom.messageChannel.enabled"]
+interface MessageChannel {
+  readonly attribute MessagePort port1;
+  readonly attribute MessagePort port2;
+};