catchErrors and waitForCompletion now based on runZonedExperimental.

tests/lib/async/catch_errors12_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';
+import 'catch_errors.dart';
 
 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 = [];
   // Tests that errors that have been delayed by several milliseconds with
   // Timers are still caught by `catchErrors`.
   catchErrors(() {
     events.add("catch error entry");
@@ skipping 13 matching lines @@
             "catch error",
             "timer error",
             "timer2 error",
             499,
           ],
           events);
       port.close();
     });
   events.add("main exit");
 }