Avoid unnecessary future in the HTTP stack, after latest cleanup.

tests/standalone/io/http_head_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 "package:expect/expect.dart";
 import "dart:io";
 
 void testHEAD(int totalConnections) {
   HttpServer.bind("127.0.0.1", 0).then((server) {
     server.listen((request) {
@@ skipping 38 matching lines @@
         .then((HttpClientResponse response) {
           Expect.equals(len, response.contentLength);
           response.listen(
             (_) => Expect.fail("Data from HEAD request"),
             onDone: requestDone);
         });
 
       client.open("HEAD", "127.0.0.1", server.port, "/testChunked$len")
         .then((request) => request.close())
         .then((HttpClientResponse response) {
-            print(response.headers);
           Expect.equals(-1, response.contentLength);
           response.listen(
             (_) => Expect.fail("Data from HEAD request"),
             onDone: requestDone);
         });
     }
   });
 }
 
 void main() {
   testHEAD(4);
 }