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

net/http/http_network_session.cc

Index: net/http/http_network_session.cc
diff --git a/net/http/http_network_session.cc b/net/http/http_network_session.cc
index a452f1e5a26dd71ee7289e8a8d67398ee08988f6..cbfb0e0f0f5c7a4bf31e5fba801095a7c8ea34f6 100644
--- a/net/http/http_network_session.cc
+++ b/net/http/http_network_session.cc
@@ -113,6 +113,7 @@ HttpNetworkSession::Params::Params()
       quic_max_number_of_lossy_connections(0),
       quic_packet_loss_threshold(1.0f),
       quic_socket_receive_buffer_size(kQuicSocketReceiveBufferSize),
+      quic_delay_tcp_race(true),
       quic_max_server_configs_stored_in_properties(0u),
       quic_clock(NULL),
       quic_random(NULL),
@@ -178,6 +179,7 @@ HttpNetworkSession::HttpNetworkSession(const Params& params)
           params.quic_threshold_public_resets_post_handshake,
           params.quic_threshold_timeouts_streams_open,
           params.quic_socket_receive_buffer_size,
+          params.quic_delay_tcp_race,
           params.quic_max_server_configs_stored_in_properties,
           params.quic_close_sessions_on_ip_change,
           params.disable_quic_on_timeout_with_open_streams,
@@ -331,7 +333,7 @@ std::unique_ptr<base::Value> HttpNetworkSession::QuicInfoToValue() const {
   dict->SetInteger("max_number_of_lossy_connections",
                    params_.quic_max_number_of_lossy_connections);
   dict->SetDouble("packet_loss_threshold", params_.quic_packet_loss_threshold);
-  dict->SetBoolean("delay_tcp_race", true);
+  dict->SetBoolean("delay_tcp_race", params_.quic_delay_tcp_race);
   dict->SetInteger("max_server_configs_stored_in_properties",
                    params_.quic_max_server_configs_stored_in_properties);
   dict->SetInteger("idle_connection_timeout_seconds",