diff -r 000000000000 -r 6474c204b198 dom/webidl/HTMLTrackElement.webidl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/webidl/HTMLTrackElement.webidl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,30 @@
+/* -*- 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/.
+ *
+ * The origin of this IDL file is
+ * http://www.whatwg.org/specs/web-apps/current-work/#the-track-element
+ */
+
+[Pref="media.webvtt.enabled"]
+interface HTMLTrackElement : HTMLElement {
+  [SetterThrows, Pure]
+  attribute DOMString kind;
+  [SetterThrows, Pure]
+  attribute DOMString src;
+  [SetterThrows, Pure]
+  attribute DOMString srclang;
+  [SetterThrows, Pure]
+  attribute DOMString label;
+  [SetterThrows, Pure]
+  attribute boolean default;
+
+  const unsigned short NONE = 0;
+  const unsigned short LOADING = 1;
+  const unsigned short LOADED = 2;
+  const unsigned short ERROR = 3;
+  readonly attribute unsigned short readyState;
+
+  readonly attribute TextTrack? track;
+};