Add zone support to streams.

tests/lib/async/catch_errors19_test.dart

+// Copyright (c) 2013, 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.
+
+import "package:expect/expect.dart";
+import 'dart:async';
+import 'dart:isolate';
+
+main() {
+  // We keep a ReceivePort open until all tests are done. This way the VM will
+  // hang if the callbacks are not invoked and the test will time out.
+  var port = new ReceivePort();
+  var events = [];
+  Stream stream = new Stream.periodic(const Duration(milliseconds: 20),
+                                      (x) => x);
+  // Test that asynchronous callbacks in the done-handler of streams (here
+  // the `catchErrors`-stream) keep a zone alive.
+  catchErrors(() {
+    var subscription;
+    subscription = stream.take(5).listen((x) {
+      events.add(x);
+    }, onDone: () {
+      new Future.delayed(const Duration(milliseconds: 30), () {
+        events.add(499);
+      });
+    });
+  }).listen((x) { events.add("outer: $x"); },
+            onDone: () {
+              Expect.listEquals([0, 1, 2, 3, 4, 499], events);
+              port.close();
+            });
+}