Revert of QUIC - enable "delay_tcp_race" parameter by default. This feature showed

ios/chrome/browser/ios_chrome_io_thread.mm

 // Copyright 2015 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 "ios/chrome/browser/ios_chrome_io_thread.h"
 
 #include <stddef.h>
 
 #include <utility>
 #include <vector>
@@ skipping 646 matching lines @@
   globals.quic_enable_non_blocking_io.CopyToIfSet(
       &params->quic_enable_non_blocking_io);
   globals.quic_prefer_aes.CopyToIfSet(&params->quic_prefer_aes);
   globals.quic_disable_disk_cache.CopyToIfSet(&params->quic_disable_disk_cache);
   globals.quic_max_number_of_lossy_connections.CopyToIfSet(
       &params->quic_max_number_of_lossy_connections);
   globals.quic_packet_loss_threshold.CopyToIfSet(
       &params->quic_packet_loss_threshold);
   globals.quic_socket_receive_buffer_size.CopyToIfSet(
       &params->quic_socket_receive_buffer_size);
+  globals.quic_delay_tcp_race.CopyToIfSet(&params->quic_delay_tcp_race);
   params->enable_quic_port_selection = false;
   globals.quic_max_packet_length.CopyToIfSet(&params->quic_max_packet_length);
   globals.quic_user_agent_id.CopyToIfSet(&params->quic_user_agent_id);
   globals.quic_supported_versions.CopyToIfSet(&params->quic_supported_versions);
   params->quic_connection_options = globals.quic_connection_options;
   globals.quic_close_sessions_on_ip_change.CopyToIfSet(
       &params->quic_close_sessions_on_ip_change);
 
   params->enable_user_alternate_protocol_ports = false;
 }
@@ skipping 87 matching lines @@
 
   if (enable_quic) {
     globals->quic_always_require_handshake_confirmation.set(
         ShouldQuicAlwaysRequireHandshakeConfirmation(quic_trial_params));
     globals->quic_disable_connection_pooling.set(
         ShouldQuicDisableConnectionPooling(quic_trial_params));
     int receive_buffer_size = GetQuicSocketReceiveBufferSize(quic_trial_params);
     if (receive_buffer_size != 0) {
       globals->quic_socket_receive_buffer_size.set(receive_buffer_size);
     }
+    globals->quic_delay_tcp_race.set(ShouldQuicDelayTcpRace(quic_trial_params));
     float load_server_info_timeout_srtt_multiplier =
         GetQuicLoadServerInfoTimeoutSrttMultiplier(quic_trial_params);
     if (load_server_info_timeout_srtt_multiplier != 0) {
       globals->quic_load_server_info_timeout_srtt_multiplier.set(
           load_server_info_timeout_srtt_multiplier);
     }
     globals->quic_enable_connection_racing.set(
         ShouldQuicEnableConnectionRacing(quic_trial_params));
     globals->quic_enable_non_blocking_io.set(
         ShouldQuicEnableNonBlockingIO(quic_trial_params));
@@ skipping 152 matching lines @@
     const VariationParameters& quic_trial_params) {
   int value;
   if (base::StringToInt(
           GetVariationParam(quic_trial_params, "receive_buffer_size"),
           &value)) {
     return value;
   }
   return 0;
 }
 
+bool IOSChromeIOThread::ShouldQuicDelayTcpRace(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "delay_tcp_race"), "true");
+}
+
 bool IOSChromeIOThread::ShouldQuicCloseSessionsOnIpChange(
     const VariationParameters& quic_trial_params) {
   return base::LowerCaseEqualsASCII(
       GetVariationParam(quic_trial_params, "close_sessions_on_ip_change"),
       "true");
 }
 
 size_t IOSChromeIOThread::GetQuicMaxPacketLength(
     const VariationParameters& quic_trial_params) {
   unsigned value;
@@ skipping 67 matching lines @@
 
   globals->system_http_network_session.reset(
       new net::HttpNetworkSession(system_params));
   globals->system_http_transaction_factory.reset(
       new net::HttpNetworkLayer(globals->system_http_network_session.get()));
   context->set_http_transaction_factory(
       globals->system_http_transaction_factory.get());
 
   return context;
 }