Adding test for DOM Subtree Modified event.

tests/html/event_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('EventTest');
 #import('../../pkg/unittest/unittest.dart');
 #import('../../pkg/unittest/html_config.dart');
 #import('dart:html');
 
 // TODO(nweiz): Make this private to testEvents when Frog supports closures with
@@ skipping 122 matching lines @@
       () => new MutationEvent('foo', new Element.tag('div'), 'red', 'blue',
           'color', MutationEvent.MODIFICATION),
       (ev) {
     Expect.equals('DIV', ev.relatedNode.tagName);
     Expect.equals('red', ev.prevValue);
     Expect.equals('blue', ev.newValue);
     Expect.equals('color', ev.attrName);
     Expect.equals(MutationEvent.MODIFICATION, ev.attrChange);
   });
 
+  test('DOMMutationEvent', () {
+    var div = new DivElement();
+    div.on['DOMSubtreeModified'].add(expectAsync1((DOMMutationEvent e) {}));
+    div.nodes.add(new SpanElement());
+  });
+
   // Issue 1005.
   // eventTest('OverflowEvent',
   //     () => new OverflowEvent(OverflowEvent.BOTH, true, true),
   //     (ev) {
   //   Expect.equals(OverflowEvent.BOTH, ev.orient);
   //   Expect.isTrue(ev.horizontalOverflow);
   //   Expect.isTrue(ev.verticalOverflow);
   // }, type: 'overflowchanged');
 
   // Issue 1005.
@@ skipping 63 matching lines @@
     Expect.isTrue(ev.metaKey);
   }, type: 'mousewheel');
 
   // HttpRequestProgressEvent has no properties to itself, so just test that
   // it doesn't error out on creation and can be dispatched.
   // Issue 1005.
   // eventTest('HttpRequestProgressEvent',
   //     () => new HttpRequestProgressEvent('foo', 5),
   //     (ev) {});
 }