Updating Polymer to derive from custom elements.

pkg/polymer/test/take_attributes_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-foo')
 class XFoo extends PolymerElement {
+  XFoo.created() : super.created();
+
   @published bool boolean = false;
   @published num number = 42;
   @published String str = "don't panic";
 }
 
 @CustomTag('x-bar')
 class XBar extends PolymerElement {
+  XBar.created() : super.created();
+
   @observable bool boolean = false;
   @observable num number = 42;
   @observable String str = "don't panic";
 }
 
 @CustomTag('x-zot')
 class XZot extends XBar {
+  XZot.created() : super.created();
   @observable num number = 84;
 }
 
 @CustomTag('x-date')
 class XDate extends PolymerElement {
+  XDate.created() : super.created();
   @observable var value = new DateTime(2013, 9, 25);
 }
 
 @CustomTag('x-array')
 class XArray extends PolymerElement {
+  XArray.created() : super.created();
   @observable List values;
 }
 
 @CustomTag('x-obj')
 class XObj extends PolymerElement {
+  XObj.created() : super.created();
   @observable var values = {};
 }
 
 main() {
   useHtmlConfiguration();
 
   test('take attributes', () {
     queryXTag(x) => document.query(x).xtag;
 
     expect(queryXTag("#foo0").boolean, true);
@@ skipping 49 matching lines @@
     expect(queryXTag("#arr1").values, [0, 1, 2]);
     expect(queryXTag("#arr2").values, [33]);
     // Object deserialization tests
     expect(queryXTag("#obj1").values, { 'name': 'Brandon',
         'nums': [1, 22, 33] });
     expect(queryXTag("#obj2").values, { "color": "Red" });
     expect(queryXTag("#obj3").values, { 'movie': 'Buckaroo Banzai',
         'DOB': '07/31/1978' });
   });
 }