Port Try Dart! to SDK 1.0.

dart/site/try/isolate_legacy.dart

+// Copyright (c) 2014, 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 trydart.isolate_legacy;
+
+import 'dart:isolate';
+import 'dart:async';
+
+ReceivePort spawnFunction(void function(SendPort port)) {
+  ReceivePort port = new ReceivePort();
+  Isolate.spawn(function, port.sendPort);
+  return port;
+}
+
+ReceivePort spawnDomFunction(void function(SendPort port)) {
+  throw 'spawnDomFunction is no more';
+}