Work around issue 6984.

utils/tests/pub/test_pub.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Test infrastructure for testing pub. Unlike typical unit tests, most pub
  * tests are integration tests that stage some stuff on the file system, run
  * pub, and then validate the results. This library provides an API to build
  * tests like that.
  */
@@ skipping 87 matching lines @@
       _server = new HttpServer();
       _server.defaultRequestHandler = (request, response) {
         var path = request.uri.replaceFirst("/", "").split("/");
         response.persistentConnection = false;
         var stream;
         try {
           stream = baseDir.load(path);
         } catch (e) {
           response.statusCode = 404;
           response.contentLength = 0;
-          response.outputStream.close();
+          closeHttpResponse(request, response);
           return;
         }
 
         var future = consumeInputStream(stream);
         future.then((data) {
           response.statusCode = 200;
           response.contentLength = data.length;
           response.outputStream.write(data);
-          response.outputStream.close();
+          closeHttpResponse(request, response);
         });
 
         future.handleException((e) {
           print("Exception while handling ${request.uri}: $e");
           response.statusCode = 500;
           response.reasonPhrase = e.message;
-          response.outputStream.close();
+          closeHttpResponse(request, response);
         });
       };
       _server.listen("127.0.0.1", 0);
       _portCompleter.complete(_server.port);
       _scheduleCleanup((_) => _closeServer());
       return null;
     });
   });
 }
 
@@ skipping 1393 matching lines @@
 /// calling [completion] is unnecessary.
 void expectLater(Future actual, matcher, {String reason,
     FailureHandler failureHandler, bool verbose: false}) {
   _schedule((_) {
     return actual.transform((value) {
       expect(value, matcher, reason: reason, failureHandler: failureHandler,
           verbose: false);
     });
   });
 }