Missed a change in the rename from initCustomEvent -> $dom_initCustomEvent.

lib/html/templates/html/interface/interface_CustomEvent.darttemplate

Index: lib/html/templates/html/interface/interface_CustomEvent.darttemplate
===================================================================
--- lib/html/templates/html/interface/interface_CustomEvent.darttemplate	(revision 0)
+++ lib/html/templates/html/interface/interface_CustomEvent.darttemplate	(working copy)
@@ -0,0 +1,14 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// WARNING: Do not edit - generated code.
+
+$!COMMENT
+abstract class $ID$EXTENDS {
+
+  factory $ID(String type, [bool canBubble = true, bool cancelable = true,
+      Object detail = null]) => _$(ID)FactoryProvider.create$ID(type, canBubble,
+      cancelable, detail);
+
+$!MEMBERS}