update custom elements and shadow dom

pkg/shadow_dom/lib/src/platform/patches-shadowdom-polyfill.js

 /*
  * Copyright 2013 The Polymer Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the LICENSE file.
  */
 (function() {
   var ShadowDOMPolyfill = window.ShadowDOMPolyfill;
   var wrap = ShadowDOMPolyfill.wrap;
 
   // patch in prefixed name
   Object.defineProperties(HTMLElement.prototype, {
     //TODO(sjmiles): review accessor alias with Arv
     webkitShadowRoot: {
       get: function() {
         return this.shadowRoot;
       }
     }
   });
 
+  // ShadowCSS needs this:
+  window.wrap = window.ShadowDOMPolyfill.wrap;
+  window.unwrap = window.ShadowDOMPolyfill.unwrap;
+
   //TODO(sjmiles): review method alias with Arv
   HTMLElement.prototype.webkitCreateShadowRoot =
       HTMLElement.prototype.createShadowRoot;
 
   // TODO(jmesserly): we need to wrap document somehow (a dart:html hook?)
   window.dartExperimentalFixupGetTag = function(originalGetTag) {
     var NodeList = ShadowDOMPolyfill.wrappers.NodeList;
     var ShadowRoot = ShadowDOMPolyfill.wrappers.ShadowRoot;
     var unwrapIfNeeded = ShadowDOMPolyfill.unwrapIfNeeded;
     function getTag(obj) {
@@ skipping 30 matching lines @@
         }
 
         obj = unwrapped;
       }
       return originalGetTag(obj);
     }
 
     return getTag;
   };
 })();