update polymer js to 0.4.0

pkg/polymer/lib/src/build/polyfill_injector.dart

 // 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.
 
 /// Includes any additional polyfills that may needed by the deployed app.
 library polymer.src.build.polyfill_injector;
 
 import 'dart:async';
 
 import 'package:barback/barback.dart';
@@ skipping 19 matching lines @@
   Future<bool> isPrimary(idOrAsset) {
     var id = idOrAsset is AssetId ? idOrAsset : idOrAsset.id;
     return new Future.value(options.isHtmlEntryPoint(id));
   }
 
   Future apply(Transform transform) {
     var logger = new BuildLogger(transform,
         convertErrorsToWarnings: !options.releaseMode,
         detailsUri: 'http://goo.gl/5HPeuP');
     return readPrimaryAsHtml(transform, logger).then((document) {
-      bool webComponentsFound = false;
+      bool dartSupportFound = false;
+      bool platformJsFound = false;
       Element dartJs;
       final dartScripts = <Element>[];
 
       for (var tag in document.querySelectorAll('script')) {
         var src = tag.attributes['src'];
         if (src != null) {
           var last = src.split('/').last;
-          if (_webComponentsJS.hasMatch(last)) {
-            webComponentsFound = true;
+          if (_platformJS.hasMatch(last)) {
+            platformJsFound = true;
+          } else if (_dartSupportJS.hasMatch(last)) {
+            dartSupportFound = true;
           } else if (last == 'dart.js') {
             dartJs = tag;
           }
         }
 
         if (tag.attributes['type'] == 'application/dart') {
           dartScripts.add(tag);
         }
       }
 
@@ skipping 28 matching lines @@
         document.body.nodes.add(parseFragment(
               '<script src="packages/browser/dart.js"></script>'));
       }
 
       _addScriptFirst(urlSegment) {
         document.head.nodes.insert(0, parseFragment(
               '<script src="packages/$urlSegment"></script>\n'));
       }
 
       var suffix = options.releaseMode ? '.js' : '.concat.js';
-      if (!webComponentsFound) {
-        _addScriptFirst('web_components/dart_support.js');
-
-        // platform.js should come before all other scripts.
-        _addScriptFirst('web_components/platform$suffix');
-      }
+      if (!dartSupportFound) _addScriptFirst('web_components/dart_support.js');
+      // platform.js should come before all other scripts.
+      if (!platformJsFound) _addScriptFirst('web_components/platform$suffix');
 
       transform.addOutput(
           new Asset.fromString(transform.primaryInput.id, document.outerHtml));
     });
   }
 }
 
-final _webComponentsJS = new RegExp(r'platform.*\.js',
-    caseSensitive: false);
+final _platformJS = new RegExp(r'platform.*\.js', caseSensitive: false);
+final _dartSupportJS = new RegExp(r'dart_support.js', caseSensitive: false);