Avoid doing concurrent DNS resolves of the same hostname

net/http/http_network_transaction.h

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_HTTP_HTTP_NETWORK_TRANSACTION_H_
 #define NET_HTTP_HTTP_NETWORK_TRANSACTION_H_
 
 #include <string>
 
 #include "base/ref_counted.h"
@@ skipping 274 matching lines @@
   CompletionCallback* user_callback_;
 
   scoped_refptr<HttpNetworkSession> session_;
 
   const HttpRequestInfo* request_;
   HttpResponseInfo response_;
 
   ProxyService::PacRequest* pac_request_;
   ProxyInfo proxy_info_;
 
-  HostResolver resolver_;
-  AddressList addresses_;
-
   ClientSocketFactory* socket_factory_;
   ClientSocketHandle connection_;
   scoped_ptr<HttpStream> http_stream_;
   bool reused_socket_;
 
   bool using_ssl_;     // True if handling a HTTPS request
   bool using_proxy_;   // True if using a proxy for HTTP (not HTTPS)
   bool using_tunnel_;  // True if using a tunnel for HTTPS
 
   // True while establishing a tunnel.  This allows the HTTP CONNECT
@@ skipping 76 matching lines @@
   // The time the host resolution started (if it indeed got started).
   base::Time host_resolution_start_time_;
 
   // The next state in the state machine.
   State next_state_;
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_NETWORK_TRANSACTION_H_