Enable the SSL_ENABLE_FDX option since we're using SSLClientSocketNSS...

net/socket/ssl_client_socket_nss.cc

 // Copyright (c) 2006-2009 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.
 
 // This file includes code SSLClientSocketNSS::DoVerifyCertComplete() derived
 // from AuthCertificateCallback() in
 // mozilla/security/manager/ssl/src/nsNSSCallbacks.cpp.
 
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
@@ skipping 281 matching lines @@
      return ERR_UNEXPECTED;
 
   rv = SSL_OptionSet(nss_fd_, SSL_ENABLE_SSL3, ssl_config_.ssl3_enabled);
   if (rv != SECSuccess)
      return ERR_UNEXPECTED;
 
   rv = SSL_OptionSet(nss_fd_, SSL_ENABLE_TLS, ssl_config_.tls1_enabled);
   if (rv != SECSuccess)
      return ERR_UNEXPECTED;
 
+  // Full duplex is not needed for HTTPS, but needed for SPDY and WebSocket.
+  rv = SSL_OptionSet(nss_fd_, SSL_ENABLE_FDX, PR_TRUE);
+  if (rv != SECSuccess)
+     return ERR_UNEXPECTED;
+
 #ifdef SSL_ENABLE_SESSION_TICKETS
   // Support RFC 5077
   rv = SSL_OptionSet(nss_fd_, SSL_ENABLE_SESSION_TICKETS, PR_TRUE);
   if (rv != SECSuccess)
      LOG(INFO) << "SSL_ENABLE_SESSION_TICKETS failed.  Old system nss?";
 #else
   #error "You need to install NSS-3.12 or later to build chromium"
 #endif
 
 #ifdef SSL_ENABLE_DEFLATE
@@ skipping 829 matching lines @@
   }
   PRErrorCode prerr = PR_GetError();
   if (prerr == PR_WOULD_BLOCK_ERROR) {
     return ERR_IO_PENDING;
   }
   LeaveFunction("");
   return NetErrorFromNSPRError(prerr);
 }
 
 }  // namespace net