Create a common directory of widgets and css.

appengine/chromium_rietveld/new_static/common/cr-action.html

 <!-- 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. -->
 
 <!--
     This is similar to a button, but appears like a link instead. It's generally
     for non-destructive actions and should never navigate the page.
 
     ex. <a is="cr-action" on-tap="{{ doSomething }}"></a>
 
@@ skipping 26 matching lines @@
                     this.fire("tap");
                     event.preventDefault();
                 }
             },
             handleClick: function(event) {
                 event.preventDefault();
             },
         });
     </script>
 </ploymer-element>