Optional binary payloads in VM service events.

runtime/bin/vmservice/observatory/test/gc_test.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.
+
 import 'package:observatory/service_io.dart';
 import 'test_helper.dart';
 
 import 'dart:async';
 
 void script() {
   List<int> data;
   var grow;
   grow = (int iterations, int size, Duration duration) {
     if (iterations <= 0) {
@@ skipping 15 matching lines @@
     if (event.eventType == 'GC' && --gcCountdown == 0) {
       completer.complete();
     }
   });
   return completer.future;
 },
 
 ];
 
 main(args) => runIsolateTests(args, tests, testeeConcurrent: script);