Create a common directory of widgets and css.

appengine/chromium_rietveld/new_static/common/forms.css

 /*
  * Copyright (c) 2014 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 .form-fields {
     display: table;
     width: 100%;
 }
@@ skipping 36 matching lines @@
 }
 
 .form-error:empty {
     padding: 0;
 }
 
 .form-warning {
     color: #9FA6AA;
     font-size: 1em;
 }