Migrate dom tests to dart:html.

tests/dom/isolates_test.dart

 #library('IsolatesTest');
 #import('../../lib/unittest/unittest.dart');
-#import('../../lib/unittest/dom_config.dart');
-#import('dart:dom');
+#import('../../lib/unittest/html_config.dart');
+#import('dart:html');
 #import('dart:json');
 #import('dart:isolate', prefix:'isolate');
 
 class PingPongIsolate extends isolate.Isolate {
   PingPongIsolate() : super.heavy();
 
   void main() {
     bool wasThrown = false;
     try {
       window.alert('Test');
@@ skipping 10 matching lines @@
 
     port.receive((message, replyTo) {
       replyTo.send(responseFor(message), null);
     });
   }
 
   static String responseFor(message) => 'response for $message';
 }
 
 main() {
-  useDomConfiguration();
+  useHtmlConfiguration();
   asyncTest('IsolateSpawn', 1, () {
     new PingPongIsolate().spawn().then((isolate.SendPort port) {
       callbackDone();
     });
   });
   asyncTest('NonDOMIsolates', 1, () {
     new PingPongIsolate().spawn().then((isolate.SendPort port) {
       final msg1 = 'foo';
       final msg2 = 'bar';
       port.call(msg1).then((response) {
         Expect.equals(PingPongIsolate.responseFor(msg1), response);
         port.call(msg2).then((response) {
           Expect.equals(PingPongIsolate.responseFor(msg2), response);
           callbackDone();
         });
       });
     });
   });
 }