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

chrome/browser/io_thread.cc

Index: chrome/browser/io_thread.cc
diff --git a/chrome/browser/io_thread.cc b/chrome/browser/io_thread.cc
index 78ce6c8a35a8bc9a7c1f2b0a923a5380b343e200..5d6949b978786da0d78f4bfb6481901a5a58e75a 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -1199,6 +1199,7 @@ void IOThread::NetworkSessionConfigurator::ConfigureQuicParams(
     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) {
@@ -1448,6 +1449,13 @@ int IOThread::NetworkSessionConfigurator::GetQuicSocketReceiveBufferSize(
 }
 
 // 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(