Print the data we get back from the tcp socket meta data service

runtime/observatory/tests/service/tcp_socket_service_test.dart

 // Copyright (c) 2015, 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 'dart:async';
 import 'dart:convert';
 import 'dart:io' as io;
 import 'package:observatory/service_io.dart';
 import 'package:unittest/unittest.dart';
 import 'test_helper.dart';
@@ skipping 18 matching lines @@
 
 var tcpTests = [
   // Initial.
   (Isolate isolate) async {
     var result = await isolate.invokeRpcNoUpgrade('__getOpenSockets', {});
     expect(result['type'], equals('_opensockets'));
     // We expect 3 sockets to be open (in this order):
     //   The server socket accepting connections, on port X
     //   The accepted connection on the client, on port Y
     //   The client connection, on port X
+    if (result['data'].length != 5) {
+      print(result['data']);
+    }
     expect(result['data'].length, equals(5));
     // The first socket will have a name like listening:127.0.0.1:X
     // The second will have a name like 127.0.0.1:Y
     // The third will have a name like 127.0.0.1:X
     expect(result['data'][0]['name'].startsWith('listening:127.0.0.1'), isTrue);
     expect(result['data'][1]['name'].startsWith('127.0.0.1:'), isTrue);
     expect(result['data'][2]['name'].startsWith('127.0.0.1:'), isTrue);
 
     var listening = await isolate.invokeRpcNoUpgrade(
         '__getSocketByID', { 'id' : result['data'][0]['id'] });
@@ skipping 108 matching lines @@
     // Stopwatch resolution on windows make us sometimes report the same value.
     if (io.Platform.isWindows) {
       expect(server['lastRead'], greaterThanOrEqualTo(client['lastWrite']));
     } else {
       expect(server['lastRead'], greaterThan(client['lastWrite']));
     }
   },
 ];
 
 main(args) async => runIsolateTests(args, tcpTests, testeeBefore:setupTCP);