Correctly create a new stream when the server requires authentication.

net/http/http_pipelined_stream.cc

Index: net/http/http_pipelined_stream.cc
diff --git a/net/http/http_pipelined_stream.cc b/net/http/http_pipelined_stream.cc
index 2183c528fcfbd749c99683af6cc4b20e73ac1b7f..6b844a6210ddae7eb0f3ca8d16c29fe9d6c290af 100644
--- a/net/http/http_pipelined_stream.cc
+++ b/net/http/http_pipelined_stream.cc
@@ -71,8 +71,10 @@ void HttpPipelinedStream::Close(bool not_reusable) {
 }
 
 HttpStream* HttpPipelinedStream::RenewStreamForAuth() {
-  // FIXME: What does this mean on a pipeline? Is it for proxies?
-  return new HttpPipelinedStream(pipeline_, pipeline_id_);
+  if (pipeline_->usable()) {
+    return pipeline_->CreateNewStream();
+  }
+  return NULL;
 }
 
 bool HttpPipelinedStream::IsResponseBodyComplete() const {