Add autofocus to the Html5NodeValidator list of standard attributes for <input>

tools/dom/src/Html5NodeValidator.dart

 // DO NOT EDIT- this file is generated from running tool/generator.sh.
 
 // 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 dart.dom.html;
 
 /**
  * A Dart DOM validator generated from Caja whitelists.
@@ skipping 221 matching lines @@
     'IMG::ismap',
     'IMG::name',
     'IMG::usemap',
     'IMG::vspace',
     'IMG::width',
     'INPUT::accept',
     'INPUT::accesskey',
     'INPUT::align',
     'INPUT::alt',
     'INPUT::autocomplete',
+    'INPUT::autofocus',
     'INPUT::checked',
     'INPUT::disabled',
     'INPUT::inputmode',
     'INPUT::ismap',
     'INPUT::list',
     'INPUT::max',
     'INPUT::maxlength',
     'INPUT::min',
     'INPUT::multiple',
     'INPUT::name',
@@ skipping 189 matching lines @@
   static bool _standardAttributeValidator(Element element, String attributeName,
       String value, _Html5NodeValidator context) {
     return true;
   }
 
   static bool _uriAttributeValidator(Element element, String attributeName,
       String value, _Html5NodeValidator context) {
     return context.uriPolicy.allowsUri(value);
   }
 }