Migrate dom tests to dart:html.

tests/dom/messageevent_test.dart

Index: tests/dom/messageevent_test.dart
diff --git a/tests/dom/messageevent_test.dart b/tests/dom/messageevent_test.dart
index fbfb9859c8df280a3cd605ae4c155eee724bd365..37335972b750df3e642f23bf647cf398175297a4 100644
--- a/tests/dom/messageevent_test.dart
+++ b/tests/dom/messageevent_test.dart
@@ -1,13 +1,13 @@
 #library('SerializedScriptValueTest');
 #import('../../lib/unittest/unittest.dart');
-#import('../../lib/unittest/dom_config.dart');
-#import('dart:dom');
+#import('../../lib/unittest/html_config.dart');
+#import('dart:html');
 
 main() {
-  useDomConfiguration();
+  useHtmlConfiguration();
 
   test('MessageEvent.initMessageEvent', () {
-      final event = document.createEvent('MessageEvent');
+      final event = document.$dom_createEvent('MessageEvent');
       event.initMessageEvent('type', false, true, 'data', 'origin', 'lastEventId', window, []);
       expect(event.type).equals('type');
       expect(event.bubbles).equals(false);