Use Chain.capture instead of runZoned

runtime/observatory/tests/service/test_helper.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.
 
 library test_helper;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'package:observatory/service_io.dart';
+import 'package:stack_trace/stack_trace.dart';
 import 'service_test_common.dart';
 
 /// Will be set to the http address of the VM's service protocol before
 /// any tests are invoked.
 String serviceHttpAddress;
 String serviceWebsocketAddress;
 
 bool _isWebSocketDisconnect(e) {
   return e is NetworkRpcException;
 }
@@ skipping 243 matching lines @@
             bool pause_on_start: false,
             bool pause_on_exit: false,
             bool trace_service: false,
             bool trace_compiler: false,
             bool verbose_vm: false,
             bool pause_on_unhandled_exceptions: false}) {
     var port = 8100;
     serviceWebsocketAddress = 'ws://localhost:$port/ws';
     serviceHttpAddress = 'http://localhost:$port';
     var name = Platform.script.pathSegments.last;
-    runZoned(() async {
+    Chain.capture(() async {
       var vm =
           new WebSocketVM(new WebSocketVMTarget(serviceWebsocketAddress));
       print('Loading VM...');
       await vm.load();
       print('Done loading VM');
 
       // Run vm tests.
       if (vmTests != null) {
         var testIndex = 1;
         var totalTests = vmTests.length;
@@ skipping 46 matching lines @@
                    trace_service, trace_compiler).then((port) async {
       if (mainArgs.contains("--gdb")) {
         var pid = process.process.pid;
         var wait = new Duration(seconds: 10);
         print("Testee has pid $pid, waiting $wait before continuing");
         sleep(wait);
       }
       serviceWebsocketAddress = 'ws://localhost:$port/ws';
       serviceHttpAddress = 'http://localhost:$port';
       var name = Platform.script.pathSegments.last;
-      runZoned(() async {
+      Chain.capture(() async {
         var vm =
             new WebSocketVM(new WebSocketVMTarget(serviceWebsocketAddress));
         print('Loading VM...');
         await vm.load();
         print('Done loading VM');
 
         // Run vm tests.
         if (vmTests != null) {
           var testIndex = 1;
           var totalTests = vmTests.length;
@@ skipping 133 matching lines @@
         mainArgs: mainArgs,
         vmTests: tests,
         pause_on_start: pause_on_start,
         pause_on_exit: pause_on_exit,
         trace_service: trace_service,
         trace_compiler: trace_compiler,
         verbose_vm: verbose_vm,
         pause_on_unhandled_exceptions: pause_on_unhandled_exceptions);
   }
 }