Use userAgent instead of webkitStartDart

pkg/browser/lib/dart.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.
 
 (function() {
 // Bootstrap support for Dart scripts on the page as this script.
-if (navigator.webkitStartDart) {
-  if (!navigator.webkitStartDart()) {
-    document.body.innerHTML = 'This build has expired.  Please download a new Dartium at http://www.dartlang.org/dartium/index.html';
-  }
-} else {
+if (navigator.userAgent.indexOf('(Dart)') === -1) {

[ricow1, 2013/10/30 06:35:25]

same comment as before

   // TODO:
   // - Support in-browser compilation.
   // - Handle inline Dart scripts.
 
   // Fall back to compiled JS. Run through all the scripts and
   // replace them if they have a type that indicate that they source
   // in Dart code.
   //
   //   <script type="application/dart" src="..."></script>
   //
   var scripts = document.getElementsByTagName("script");
   var length = scripts.length;
   for (var i = 0; i < length; ++i) {
     if (scripts[i].type == "application/dart") {
       // Remap foo.dart to foo.dart.js.
       if (scripts[i].src && scripts[i].src != '') {
         var script = document.createElement('script');
         script.src = scripts[i].src.replace(/\.dart(?=\?|$)/, '.dart.js');
         var parent = scripts[i].parentNode;
         // TODO(vsm): Find a solution for issue 8455 that works with more
         // than one script.
         document.currentScript = script;
         parent.replaceChild(script, scripts[i]);
       }
     }
   }
 }
 })();