Don't implicitly run "pub get".

test/serve/does_not_serve_dart_in_release_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.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 pub_tests;
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 import 'utils.dart';
 
@@ skipping 23 matching lines @@
             """
             import 'package:foo/foo.dart';
             main() => print('hello');
             """),
         d.dir("sub", [
           d.file("sub.dart", "main() => 'foo';"),
         ])
       ])
     ]).create();
 
-    pubServe(shouldGetFirst: true, args: ["--mode", "release"]);
+    pubGet();
+    pubServe(args: ["--mode", "release"]);
     requestShould404("file.dart");
     requestShould404("packages/myapp/lib.dart");
     requestShould404("packages/foo/foo.dart");
     requestShould404("sub/sub.dart");
     endPubServe();
   });
 }