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

pkg/polymer/test/register_test.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.
 
 import 'dart:html';
 import 'package:unittest/unittest.dart';
 import 'package:unittest/html_config.dart';
 import 'package:polymer/polymer.dart';
 
 @CustomTag('x-html')
 class XHtmlElement extends PolymerElement {
   XHtmlElement.created() : super.created();
 }
 
 @CustomTag('x-html-two')
 class XHtml2Element extends XHtmlElement {
   XHtml2Element.created() : super.created();
 }
 
 @CustomTag('x-div')
 class XDivElement extends DivElement with Polymer, Observable {
   XDivElement.created() : super.created();
 }
 
 @CustomTag('x-div-two')
 class XDiv2Element extends XDivElement {
   XDiv2Element.created() : super.created();
 }
 
+@initMethod
 main() {
-  initPolymer();
   useHtmlConfiguration();
 
   setUp(() => Polymer.onReady);
 
   test('elements upgraded', () {
     expect(querySelector('x-html') is XHtmlElement, isTrue);
     expect(querySelector('x-html-two') is XHtml2Element, isTrue);
     expect(querySelector('#x-div') is XDivElement, isTrue);
     expect(querySelector('#x-div-two') is XDiv2Element, isTrue);
   });
 }