Remove the wrapStream workaround for issue 8310.

pkg/http/lib/src/utils.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.
 
 library utils;
 
 import 'dart:async';
 import 'dart:crypto';
 import 'dart:io';
 import 'dart:scalarlist';
@@ skipping 232 matching lines @@
 /// The return values of all [Future]s are discarded. Any errors will cause the
 /// iteration to stop and will be piped through the return value.
 Future forEachFuture(Iterable input, Future fn(element)) {
   var iterator = input.iterator;
   Future nextElement(_) {
     if (!iterator.moveNext()) return new Future.immediate(null);
     return fn(iterator.current).then(nextElement);
   }
   return nextElement(null);
 }
-
-// TODO(nweiz): remove this when issue 8310 is fixed.
-/// Returns a [Stream] identical to [stream], but piped through a new
-/// [StreamController]. This exists to work around issue 8310.
-Stream wrapStream(Stream stream) {
-  var controller = stream.isBroadcast
-      ? new StreamController.broadcast()
-      : new StreamController();
-  stream.listen(controller.add,
-      onError: (e) => controller.signalError(e),
-      onDone: controller.close);
-  return controller.stream;
-}