Use @Native annotation on dart2js DOM native classes

tools/dom/templates/html/impl/impl_Screen.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.
 
 part of $LIBRARYNAME;
 
 @DocsEditable()
-$(ANNOTATIONS)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
+$(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS {
 
   @DomName('Screen.availHeight')
   @DomName('Screen.availLeft')
   @DomName('Screen.availTop')
   @DomName('Screen.availWidth')
   Rectangle get available => new Rectangle(_availLeft, _availTop, _availWidth,
       _availHeight);
 $!MEMBERS}