Fix broken test.

tests/html/element_classes_test.dart

 // Copyright (c) 2011, 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 ElementTest;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_config.dart';
 import 'dart:collection';
 import 'dart:html';
 
@@ skipping 55 matching lines @@
     }
     expect(classes, orderedEquals(['foo', 'bar', 'baz']));
   });
 
   test('map', () {
     expect(makeClassSet().map((c) => c.toUpperCase()).toList(),
         orderedEquals(['FOO', 'BAR', 'BAZ']));
   });
 
   test('where', () {
-    expect(makeClassSet().where((c) => c.contains('a')).toSet(),
+    expect(makeClassSet().where((c) => c.contains('a')).toList(),
         orderedEquals(['bar', 'baz']));
   });
 
   test('every', () {
     expect(makeClassSet().every((c) => c is String), isTrue);
     expect(makeClassSet().every((c) => c.contains('a')), isFalse);
   });
 
   test('any', () {
     expect(makeClassSet().any((c) => c.contains('a')), isTrue);
@@ skipping 91 matching lines @@
   test('order', () {
     var classes = makeClassSet();
     classes.add('aardvark');
     expect(classes, orderedEquals(['foo', 'bar', 'baz', 'aardvark']));
     classes.toggle('baz');
     expect(classes, orderedEquals(['foo', 'bar', 'aardvark']));
     classes.toggle('baz');
     expect(classes, orderedEquals(['foo', 'bar', 'aardvark', 'baz']));
   });
 }