update elements and fix some bugs

test/paper_radio_group_basic_test.dart

 // Copyright (c) 2015, 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.
 @TestOn('browser')
 library polymer_elements.test.paper_radio_group_basic_test;
 
 import 'dart:async';
 import 'package:test/test.dart';
 import 'package:web_components/web_components.dart';
 import 'package:polymer_elements/paper_radio_group.dart';
 import 'common.dart';
 
 main() async {
   await initWebComponents();
 
   group('defaults', () {
     var LEFT_ARROW = 37;
     var RIGHT_ARROW = 39;
+
     test('group can have no selection', () {
       PaperRadioGroup g = fixture('NoSelection');
       expect(g.selected, isNull);
       var items = g.items;
       expect(items.length, equals(3));
       expect(items[0].checked, isFalse);
       expect(items[1].checked, isFalse);
       expect(items[2].checked, isFalse);
     });
+
     test('group can have a selection', () {
       PaperRadioGroup g = fixture('WithSelection');
       expect(g.selected, isNotNull);
       var items = g.items;
       expect(items.length, equals(3));
       expect(items[0].checked, isTrue);
       expect(items[1].checked, isFalse);
       expect(items[2].checked, isFalse);
       expect(items[0].attributes['name'], equals(g.selected));
     });
@@ skipping 59 matching lines @@
       await completer.future;
     });
 
     test('clicking the selected item should not deselect', () async {
       PaperRadioGroup g = fixture('WithSelection');
       var items = g.items;
       expect(items[0].checked, isTrue);
       tap(items[0]);
       // The selection should not change, but wait for a little bit just
       // in case it would and an event would be fired.
-      await wait(200);
+      await wait(1);
 
       expect(items[0].checked, isTrue);
       expect(items[1].checked, isFalse);
       expect(items[2].checked, isFalse);
     });
+    
+    test('clicking the selected item should deselect if allow-empty-selection is set', () async {
+      var g = fixture('WithSelection');
+      g.allowEmptySelection = true;
+      var items = g.items;
+
+      expect(items[0].checked, true);
+      tap(items[0]);
+
+      // The selection should not change, but wait for a little bit just
+      // in case it would and an event would be fired.
+      await wait(1);
+
+      expect(items[0].checked, false);
+      expect(items[1].checked, false);
+      expect(items[2].checked, false);
+    });
   });
 }