Use @Native annotation on dart2js DOM native classes

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

 // 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.
 
 part of $LIBRARYNAME;
 
 @DocsEditable()
-$(ANNOTATIONS)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
+$(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS {
 $!MEMBERS
 
   @DomName('Touch.clientX')
   @DomName('Touch.clientY')
   Point get client => new Point(_clientX, _clientY);
 
   @DomName('Touch.pageX')
   @DomName('Touch.pageY')
   Point get page => new Point(_pageX, _pageY);
 
   @DomName('Touch.screenX')
   @DomName('Touch.screenY')
   Point get screen => new Point(_screenX, _screenY);
 }