Make isolate tests work on drt (and hopefully dartium).

tests/isolate/request_reply_test.dart

 // Copyright (c) 2012, 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 RequestReplyTest;
 
 import 'dart:isolate';
-import '../../pkg/unittest/lib/unittest.dart';
+import 'package:unittest/unittest.dart';
+import "remote_unittest_helper.dart";
 
 void entry(initPort) {
   ReceivePort port = new ReceivePort();
   initPort.send(port.sendPort);
   port.listen((pair) {
     var message = pair[0];
     SendPort replyTo = pair[1];
     replyTo.send(message + 87);
     port.close();
   });
 }
 
-void main() {
+void main([args, port]) {
+  if (testRemote(main, port)) return;
   test("send", () {
     ReceivePort init = new ReceivePort();
     Isolate.spawn(entry, init.sendPort);
     init.first.then(expectAsync1((port) {
       ReceivePort reply = new ReceivePort();
       port.send([99, reply.sendPort]);
       reply.listen(expectAsync1((message) {
         expect(message, 99 + 87);
         reply.close();
       }));
     }));
   });
 }