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

net/http/http_network_session.h

Index: net/http/http_network_session.h
diff --git a/net/http/http_network_session.h b/net/http/http_network_session.h
index d122775116bacf191d3e24af28597f0fc140f27f..41e172bedb7c8bc2d9e283271fe60ce9ee9d9391 100644
--- a/net/http/http_network_session.h
+++ b/net/http/http_network_session.h
@@ -138,6 +138,9 @@ class NET_EXPORT HttpNetworkSession
     float quic_packet_loss_threshold;
     // Size in bytes of the QUIC DUP socket receive buffer.
     int quic_socket_receive_buffer_size;
+    // Delay starting a TCP connection when QUIC believes it can speak
+    // 0-RTT to a server.
+    bool quic_delay_tcp_race;
     // Maximum number of server configs that are to be stored in
     // HttpServerProperties, instead of the disk cache.
     size_t quic_max_server_configs_stored_in_properties;