Refactor Future constructors.

utils/tests/pub/validator/dependency_test.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.
 
 import 'dart:async';
 import 'dart:json' as json;
 
 import 'package:http/http.dart' as http;
 import 'package:http/testing.dart';
 import 'package:pathos/path.dart' as path;
@@ skipping 20 matching lines @@
 }
 
 /// Sets up a test package with dependency [dep] and mocks a server with
 /// [hostedVersions] of the package available.
 setUpDependency(Map dep, {List<String> hostedVersions}) {
   useMockClient(new MockClient((request) {
     expect(request.method, equals("GET"));
     expect(request.url.path, equals("/packages/foo.json"));
 
     if (hostedVersions == null) {
-      return new Future.immediate(new http.Response("not found", 404));
+      return new Future.value(new http.Response("not found", 404));
     } else {
-      return new Future.immediate(new http.Response(json.stringify({
+      return new Future.value(new http.Response(json.stringify({
         "name": "foo",
         "uploaders": ["nweiz@google.com"],
         "versions": hostedVersions
       }), 200));
     }
   }));
 
   d.dir(appPath, [
     d.libPubspec("test_pkg", "1.0.0", deps: [dep])
   ]).create();
@@ skipping 187 matching lines @@
       d.dir(appPath, [
         d.libPubspec("test_pkg", "1.0.0", deps: [
           {'hosted': {'name': 'test_pkg', 'version': '>=1.0.0'}}
         ])
       ]).create();
 
       expectValidationWarning(dependency);
     });
   });
 }