Revert r13127.

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 13128)
+++ lib/html/templates/html/interface/interface_CustomEvent.darttemplate	(working copy)
@@ -1,14 +0,0 @@
-// 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}