Turn on Polymer TodoMVC tests on Dart buildbots

pkg/polymer/lib/boot.js

 // 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.
 
 // This script dynamically prepares a set of files to run polymer.dart. It uses
 // the html_import polyfill to search for all imported files, then
 // it inlines all <polymer-element> definitions on the top-level page (needed by
 // registerPolymerElement), and it removes script tags that appear inside
 // those tags. It finally rewrites the main entrypoint to call an initialization
 // function on each of the declared <polymer-elements>.
@@ skipping 64 matching lines @@
       // (changing to text/javascript hides the warning, but seems wrong).
       return "data:application/dart;base64," + window.btoa(script.textContent);
     }
   }
 
   // Moves <polymer-elements> from imported documents into the top-level page.
   function inlinePolymerElements(content, ref, seen) {
     if (!seen) seen = {};
     var links = content.querySelectorAll('link[rel="import"]');
     for (var i = 0; i < links.length; i++) {
-      var link = links[i].import;
+      var link = links[i];
+      // TODO(jmesserly): figure out why ".import" fails in content_shell but
+      // works in Dartium.
+      if (link.import && link.import.href) link = link.import;
+
       if (seen[link.href]) continue;
       seen[link.href] = link;
       inlinePolymerElements(link.content, ref, seen);
     }
 
     if (content != document) { // no need to do anything for the top-level page
       var elements = content.querySelectorAll('polymer-element');
       for (var i = 0; i < elements.length; i++)  {
         document.body.insertBefore(elements[i], ref);
       }
@@ skipping 53 matching lines @@
     alreadyRan = true;
     var ref = document.body.children[0];
     inlinePolymerElements(document, ref);
     mergeScripts();
     if (!navigator.webkitStartDart()) {
       document.body.innerHTML = 'This build has expired. Please download a ' +
           'new Dartium at http://www.dartlang.org/dartium/index.html';
     }
   });
 })();