diff -r 000000000000 -r 6474c204b198 dom/webidl/WebComponents.webidl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/webidl/WebComponents.webidl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,28 @@
+/* -*- 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://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/custom/index.html
+ *
+ * Copyright © 2012 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C
+ * liability, trademark and document use rules apply.
+ */
+
+callback LifecycleCreatedCallback = void();
+callback LifecycleAttachedCallback = void();
+callback LifecycleDetachedCallback = void();
+callback LifecycleAttributeChangedCallback = void(DOMString attrName, DOMString? oldValue, DOMString? newValue);
+
+dictionary LifecycleCallbacks {
+  LifecycleCreatedCallback? createdCallback;
+  LifecycleAttachedCallback? attachedCallback;
+  LifecycleDetachedCallback? detachedCallback;
+  LifecycleAttributeChangedCallback? attributeChangedCallback;
+};
+
+dictionary ElementRegistrationOptions {
+  object? prototype = null;
+  DOMString? extends = null;
+};