Implement zero-copy SSL buffers.

net/socket/ssl_client_socket_openssl.h

 // Copyright (c) 2012 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_SOCKET_SSL_CLIENT_SOCKET_OPENSSL_H_
 #define NET_SOCKET_SSL_CLIENT_SOCKET_OPENSSL_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 169 matching lines @@
   // Adds the SignedCertificateTimestamps from ct_verify_result_ to |ssl_info|.
   // SCTs are held in three separate vectors in ct_verify_result, each
   // vetor representing a particular verification state, this method associates
   // each of the SCTs with the corresponding SCTVerifyStatus as it adds it to
   // the |ssl_info|.signed_certificate_timestamps list.
   void AddSCTInfoToSSLInfo(SSLInfo* ssl_info) const;
 
   bool transport_send_busy_;
   bool transport_recv_busy_;
 
-  scoped_refptr<DrainableIOBuffer> send_buffer_;
-  scoped_refptr<IOBuffer> recv_buffer_;
+  // Buffers which are shared by BoringSSL and SSLClientSocketOpenSSL.
+  // GrowableIOBuffer is used to keep ownership and setting offset.
+  scoped_refptr<GrowableIOBuffer> send_buffer_;
+  scoped_refptr<GrowableIOBuffer> recv_buffer_;
 
   CompletionCallback user_connect_callback_;
   CompletionCallback user_read_callback_;
   CompletionCallback user_write_callback_;
 
   // Used by Read function.
   scoped_refptr<IOBuffer> user_read_buf_;
   int user_read_buf_len_;
 
   // Used by Write function.
@@ skipping 109 matching lines @@
   // pinning failure. It is a (somewhat) human-readable string.
   std::string pinning_failure_log_;
 
   BoundNetLog net_log_;
   base::WeakPtrFactory<SSLClientSocketOpenSSL> weak_factory_;
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_SSL_CLIENT_SOCKET_OPENSSL_H_