[package:mdv] fix error from dartanalyzer

pkg/mdv/test/element_bindings_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 node_bindings_test;
 
 import 'dart:async';
 import 'dart:html';
 import 'package:mdv/mdv.dart' as mdv;
 import 'package:observe/observe.dart';
@@ skipping 354 matching lines @@
     var model = toSymbolMap({'a': {'b': false}});
     input.bind('checked', model, 'a.b');
 
     input.click();
     expect(model[sym('a')][sym('b')], true);
 
     input.click();
     expect(model[sym('a')][sym('b')], false);
   });
 
-  test('Select selectedIndex', function() {
+  test('Select selectedIndex', () {
     var select = new SelectElement();
     testDiv.append(select);
     var option0 = select.append(new OptionElement());
     var option1 = select.append(new OptionElement());
     var option2 = select.append(new OptionElement());
 
     var model = toSymbolMap({'val': 2});
 
     select.bind('selectedIndex', model, 'val');
     deliverChangeRecords();
@@ skipping 12 matching lines @@
 
     var model = toSymbolMap({'foo': 'bar'});
     el.attributes['foo'] = '{{foo}} {{foo}}';
     template.model = model;
 
     deliverChangeRecords();
     el = testDiv.nodes[1];
     expect(el.attributes['foo'], 'bar bar');
   });
 }