Add additional check to vmservice/websocket_client test.

tools/apps/update_homebrew/bin/update_homebrew.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.
 
 library update_homebrew;
 
 import 'dart:io';
 import 'dart:convert';
 import 'dart:async';
 import 'package:http/http.dart' as http;
@@ skipping 28 matching lines @@
   var client = new http.Client();
   var api = new storage.StorageApi(client);
   return api.objects.get('dart-archive',
                          'channels/$channel/release/$revision/VERSION',
                          downloadOptions: DownloadOptions.FullMedia)
       .then((Media media) => JSON.fuse(ASCII).decoder.bind(media.stream).first)
       .then((versionObject) => versionObject['version'])
       .whenComplete(client.close);
 }
 
-Future<Map> setCurrentRevisions(Map revisions) {
+Future setCurrentRevisions(Map revisions) {
   return new File('$repository/dart.rb')
     .readAsLines()
     .then((lines) {
       for (var channel in CHANNELS) {
         final regExp = new RegExp('channels/$channel/release/(\\d*)/sdk');
         revisions[channel] =
             regExp.firstMatch(lines.firstWhere(regExp.hasMatch)).group(1);
       }
     });
 }
 
-Future<Map> setHashes(Map revisions, Map hashes) {
+Future setHashes(Map revisions, Map hashes) {
   List waitOn = [];
   for (var channel in CHANNELS) {
     hashes[channel] = {};
     for (var file in FILES) {
       waitOn.add(getHash256(channel, revisions[channel], file).then((hash) {
         hashes[channel][file] = hash;
       }));
     }
   }
   return Future.wait(waitOn);
@@ skipping 167 matching lines @@
         repository = tempDir.path;
       })
       .then((_) => runGit(
           ['clone', 'git@github.com:dart-lang/homebrew-dart.git', '.']))
       .then((_) => writeHomebrewInfo(channel, revision))
       .then((_) => runGit(['commit', '-a', '-m',
                            'Updated $channel branch to revision $revision']))
       .then((_) => runGit(['push']))
       .whenComplete(() => new Directory(repository).delete(recursive: true));
 }