Use @Native annotation on dart2js DOM native classes

tools/dom/templates/html/impl/impl_CompositionEvent.darttemplate

 // Copyright (c) 2013, 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.
 
 part of $LIBRARYNAME;
 
-$(ANNOTATIONS)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
+$(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS {
   factory $CLASSNAME(String type,
       {bool canBubble: false, bool cancelable: false, Window view,
       String data}) {
     if (view == null) {
       view = window;
     }
     var e = document._createEvent("CompositionEvent");
     e._initCompositionEvent(type, canBubble, cancelable, view, data);
     return e;
   }
 $!MEMBERS
 }