Refactor test servers to make them less global.

test/descriptor.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.
 
 /// Pub-specific scheduled_test descriptors.
 import 'package:oauth2/oauth2.dart' as oauth2;
 import 'package:pub/src/io.dart';
 import 'package:pub/src/utils.dart';
 import 'package:scheduled_test/descriptor.dart';
 import 'package:scheduled_test/scheduled_server.dart';
@@ skipping 135 matching lines @@
   });
 
   return hostedCache(contents);
 }
 
 /// Describes the main cache directory containing cached hosted packages
 /// downloaded from the mock package server.
 Descriptor hostedCache(Iterable<Descriptor> contents) {
   return dir(cachePath, [
     dir('hosted', [
-      async(port.then((p) => dir('localhost%58$p', contents)))
+      async(globalServer.port.then((p) => dir('localhost%58$p', contents)))
     ])
   ]);
 }
 
 /// Describes the file in the system cache that contains the client's OAuth2
 /// credentials. The URL "/token" on [server] will be used as the token
 /// endpoint for refreshing the access token.
 Descriptor credentialsFile(
     ScheduledServer server,
     String accessToken,
@@ skipping 22 matching lines @@
 /// are located on disk. If the strings are semantic versions, then the packages
 /// are located in the system cache; otherwise, the strings are interpreted as
 /// relative `file:` URLs.
 ///
 /// Validation checks that the `.packages` file exists, has the expected
 /// entries (one per key in [dependencies]), each with a path that contains
 /// either the version string (for a reference to the pub cache) or a
 /// path to a path dependency, relative to the application directory.
 Descriptor packagesFile([Map dependencies]) =>
   new PackagesFileDescriptor(dependencies);