Practically remove boot.js, adds the initialization from the Dart side of

pkg/polymer/test/event_path_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.
 
 library polymer.test.web.event_path_test;
 
 import 'dart:html';
 import 'package:polymer/polymer.dart';
 import 'package:unittest/html_config.dart';
 import 'package:unittest/unittest.dart';
 
-main() {
+@initMethod _main() {
   useHtmlConfiguration();
 
   setUp(() => Polymer.onReady);
 
   test('bubbling in the right order', () {
     var item1 = query('#item1');
     var menuButton = query('#menuButton');
     // Note: polymer uses automatic node finding (menuButton.$.menu)
     // also note that their node finding code also reachs into the ids
     // from the parent shadow (menu.$.selectorContent instead of
@@ skipping 27 matching lines @@
       expect(node, isNotNull, reason: "Should not be null at $i");
       node.on['x'].listen(expectAsync1((e) {
         expect(e.currentTarget, node);
         expect(x++, i);
       }));
     }
 
     item1.dispatchEvent(new Event('x', canBubble: true));
   });
 }