Bring back initPolymer, allow boot.js only if using "polymer_experimental.html".

pkg/polymer/e2e_test/bad_import3/test/import_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.
 
-// Regression test for dart2js, that used to emit wrong code on is
-// checks of native classes that are not instantiated.
+/// Tests how canonicalization works when using the deployed app.
+library bad_import3.import_test;
 
-import 'dart:html';
 import 'package:unittest/unittest.dart';
 import 'package:unittest/html_config.dart';
+import 'package:polymer/polymer.dart';
 
-var a = [new Object()];
-
+import 'package:bad_import3/a.dart';
 main() {
+  initPolymer();
   useHtmlConfiguration();
 
-  test('is', () {
-    expect(a[0] is Node, isFalse);
+  setUp(() => Polymer.onReady);
+
+  test('html import', () {
+    expect(a, 0, reason: 'html import was not resolved correctly.');
   });
 }