Replace bootstrap logic with 'boot.js', use 'component/dart' mime-type and add

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';
 import 'package:html5lib/dom.dart' show
     Document, DocumentFragment, Element, Node;
 import 'package:html5lib/parser.dart' show parseFragment;
 import 'common.dart';
 
 /// Ensures that any scripts and polyfills needed to run a polymer application
-/// are included. For example, this transformer will ensure that there is a
-/// script tag that loads the polyfills and interop.js (used for css shimming).
+/// are included.
 ///
 /// This step also replaces "packages/browser/dart.js" and the Dart script tag
 /// with a script tag that loads the dart2js compiled code directly.
 class PolyfillInjector extends Transformer with PolymerTransformer {
   final TransformOptions options;
 
   PolyfillInjector(this.options);
 
   /// Only run on entry point .html files.
   Future<bool> isPrimary(Asset input) =>
       new Future.value(options.isHtmlEntryPoint(input.id));
 
   Future apply(Transform transform) {
     return readPrimaryAsHtml(transform).then((document) {
       bool webComponentsFound = false;
-      bool jsInteropFound = 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 (last == 'interop.js') {
-            jsInteropFound = true;
-          } else if (_webComponentsJS.hasMatch(last)) {
+          if (_webComponentsJS.hasMatch(last)) {
             webComponentsFound = true;
           } else if (last == 'dart.js') {
             dartJs = tag;
           }
         }
 
         if (tag.attributes['type'] == 'application/dart') {
           dartScripts.add(tag);
         }
       }
@@ skipping 26 matching lines @@
       } else if (dartJs == null) {
         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'));
       }
 
-      // JS interop code is required for Polymer CSS shimming.
-      if (!jsInteropFound) _addScriptFirst('browser/interop.js');
-
       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');
       }
 
       transform.addOutput(
           new Asset.fromString(transform.primaryInput.id, document.outerHtml));
     });
   }
 }
 
 final _webComponentsJS = new RegExp(r'platform.*\.js',
     caseSensitive: false);