QUIC - Add back to code to experiment with delay_tcp_race. By default,

chrome/browser/io_thread.cc

 // 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.
 
 #include "chrome/browser/io_thread.h"
 
 #include <utility>
 #include <vector>
 
 #include "base/base64.h"
@@ skipping 1181 matching lines @@
 
   if (params->enable_quic) {
     params->quic_always_require_handshake_confirmation =
         ShouldQuicAlwaysRequireHandshakeConfirmation(quic_trial_params);
     params->quic_disable_connection_pooling =
         ShouldQuicDisableConnectionPooling(quic_trial_params);
     int receive_buffer_size = GetQuicSocketReceiveBufferSize(quic_trial_params);
     if (receive_buffer_size != 0) {
       params->quic_socket_receive_buffer_size = receive_buffer_size;
     }
+    params->quic_delay_tcp_race = ShouldQuicDelayTcpRace(quic_trial_params);
     float load_server_info_timeout_srtt_multiplier =
         GetQuicLoadServerInfoTimeoutSrttMultiplier(quic_trial_params);
     if (load_server_info_timeout_srtt_multiplier != 0) {
       params->quic_load_server_info_timeout_srtt_multiplier =
           load_server_info_timeout_srtt_multiplier;
     }
     params->quic_enable_connection_racing =
         ShouldQuicEnableConnectionRacing(quic_trial_params);
     params->quic_enable_non_blocking_io =
         ShouldQuicEnableNonBlockingIO(quic_trial_params);
@@ skipping 229 matching lines @@
   int value;
   if (base::StringToInt(GetVariationParam(quic_trial_params,
                                           "receive_buffer_size"),
                         &value)) {
     return value;
   }
   return 0;
 }
 
 // static
+bool IOThread::NetworkSessionConfigurator::ShouldQuicDelayTcpRace(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "delay_tcp_race"), "true");
+}
+
+// static
 bool IOThread::NetworkSessionConfigurator::ShouldQuicCloseSessionsOnIpChange(
     const VariationParameters& quic_trial_params) {
   return base::LowerCaseEqualsASCII(
       GetVariationParam(quic_trial_params, "close_sessions_on_ip_change"),
       "true");
 }
 
 // static
 int IOThread::NetworkSessionConfigurator::GetQuicIdleConnectionTimeoutSeconds(
     const VariationParameters& quic_trial_params) {
@@ skipping 238 matching lines @@
   // TODO(rtenneti): We should probably use HttpServerPropertiesManager for the
   // system URLRequestContext too. There's no reason this should be tied to a
   // profile.
   return context;
 }
 
 const metrics::UpdateUsagePrefCallbackType&
 IOThread::GetMetricsDataUseForwarder() {
   return metrics_data_use_forwarder_;
 }