Fixing SVGElement.classes.

tests/html/svgelement_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 SVGElementTest;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_individual_config.dart';
 import 'dart:html';
 import 'dart:svg';
 
@@ skipping 177 matching lines @@
     });
   });
 
   group('elementset', () {
     test('set', () {
       final el = new SVGSVGElement();
       el.elements = [new SVGElement.tag("circle"), new SVGElement.tag("path")];
       expect(el.innerHTML, '<circle></circle><path></path>');
     });
   });
+
+  group('css', () {
+    test('classes', () {
+      var el = new SVGElement.tag("circle");
+      var classes = el.classes;
+      expect(el.classes.length, 0);
+      classes.toggle('foo');
+      expect(el.classes.length, 1);
+      classes.toggle('foo');
+      expect(el.classes.length, 0);
+    });
+  });
 }