Don't read message-body for HEAD responses.

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 245 matching lines @@
   // we want to throw away.  The response body is typically a small error
   // page just a few hundred bytes long.
   enum { kDrainBodyBufferSize = 1024 };
 
   // The position where status line starts; -1 if not found yet.
   int header_buf_http_offset_;
 
   // Indicates the content length remaining to read.  If this value is less
   // than zero (and chunked_decoder_ is null), then we read until the server
   // closes the connection.
-  int64 content_length_;
+  int64 response_body_length_;
 
   // Keeps track of the number of response body bytes read so far.
-  int64 content_read_;
+  int64 response_body_read_;
 
   scoped_ptr<HttpChunkedDecoder> chunked_decoder_;
 
   // User buffer and length passed to the Read method.
   scoped_refptr<IOBuffer> read_buf_;
   int read_buf_len_;
 
   enum State {
     STATE_RESOLVE_PROXY,
     STATE_RESOLVE_PROXY_COMPLETE,
@@ skipping 17 matching lines @@
     STATE_DRAIN_BODY_FOR_AUTH_RESTART_COMPLETE,
     STATE_NONE
   };
   State next_state_;
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_NETWORK_TRANSACTION_H_