Migrated test block 167 to Dart 2.0.

tests/lib_strong/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:async_helper/async_helper.dart';
-import "package:expect/expect.dart";
-import 'dart:async';
-import 'catch_errors.dart';
-
-main() {
-  asyncStart();
-  Completer done = new Completer();
-
-  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);
-        done.complete(true);
-      });
-    });
-  }).listen((x) {
-    events.add("outer: $x");
-  }, onDone: () {
-    Expect.fail("Unexpected callback");
-  });
-
-  done.future.whenComplete(() {
-    // Give handlers time to run.
-    Timer.run(() {
-      Expect.listEquals([0, 1, 2, 3, 4, 499], events);
-      asyncEnd();
-    });
-  });
-}