catchErrors and waitForCompletion now based on runZonedExperimental.

tests/lib/async/run_zoned5_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();
-  // Make sure `catchErrors` shuts down the error stream when the synchronous
-  // operation is done and there isn't any asynchronous pending callback.
-  catchErrors(() {
-    return 'allDone';
-  }).listen((x) {
-      Expect.fail("Unexpected callback");
-    },
-    onDone: () {
-      port.close();
-    });
+  // Ensure that `runZoned`'s onError handles synchronous errors.
+  bool sawException = false;
+  runZonedExperimental(() { throw 0; },
+                       onError: (e) {
+                         Expect.equals(0, e);
+                         port.close();
+                         return true;
+                       });
 }