diff -r 000000000000 -r 6474c204b198 dom/webidl/TransitionEvent.webidl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/webidl/TransitionEvent.webidl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,25 @@
+/* -*- 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/.
+ *
+ * Transition events are defined in:
+ * http://www.w3.org/TR/css3-transitions/#transition-events-
+ * http://dev.w3.org/csswg/css3-transitions/#transition-events-
+ *
+ * Copyright © 2012 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C
+ * liability, trademark and document use rules apply.
+ */
+
+[Constructor(DOMString type, optional TransitionEventInit eventInitDict)]
+interface TransitionEvent : Event {
+  readonly attribute DOMString propertyName;
+  readonly attribute float     elapsedTime;
+  readonly attribute DOMString pseudoElement;
+};
+
+dictionary TransitionEventInit : EventInit {
+  DOMString propertyName = "";
+  float elapsedTime = 0;
+  DOMString pseudoElement = "";
+};