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

tests/isolate/stacktrace_message_test.dart

Index: tests/isolate/stacktrace_message_test.dart
diff --git a/tests/isolate/stacktrace_message_test.dart b/tests/isolate/stacktrace_message_test.dart
index 56ec95f17a0fbe625f2e6ff9205ec5f08adc93cb..c22fa0117124f29f1acd7b8da101414aeb6659b7 100644
--- a/tests/isolate/stacktrace_message_test.dart
+++ b/tests/isolate/stacktrace_message_test.dart
@@ -3,12 +3,17 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:isolate';
+import "package:unittest/unittest.dart";
+import "remote_unittest_helper.dart";
 
-main() {
-  ReceivePort reply = new ReceivePort();
-  Isolate.spawn(runTest, reply.sendPort);
-  reply.first.then((StackTrace stack) {
-    print(stack);
+void main([args, port]) {
+  if (testRemote(main, port)) return;
+  test("stacktrace_message", () {
+    ReceivePort reply = new ReceivePort();
+    Isolate.spawn(runTest, reply.sendPort);
+    reply.first.then(expectAsync1((StackTrace stack) {
+      print(stack);
+    }));
   });
 }