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

net/quic/quic_stream_factory.h

Index: net/quic/quic_stream_factory.h
diff --git a/net/quic/quic_stream_factory.h b/net/quic/quic_stream_factory.h
index d1aab0136bda21c8959cdbef6db83edc6e186b78..542687f5e5f4203b5c30a3899ae662191afe346f 100644
--- a/net/quic/quic_stream_factory.h
+++ b/net/quic/quic_stream_factory.h
@@ -178,6 +178,7 @@ class NET_EXPORT_PRIVATE QuicStreamFactory
       int threshold_timeouts_with_streams_open,
       int threshold_public_resets_post_handshake,
       int socket_receive_buffer_size,
+      bool delay_tcp_race,
       int max_server_configs_stored_in_properties,
       bool close_sessions_on_ip_change,
       bool disable_quic_on_timeout_with_open_streams,
@@ -345,6 +346,8 @@ class NET_EXPORT_PRIVATE QuicStreamFactory
 
   int socket_receive_buffer_size() const { return socket_receive_buffer_size_; }
 
+  bool delay_tcp_race() const { return delay_tcp_race_; }
+
  private:
   class Job;
   friend class test::QuicStreamFactoryPeer;
@@ -535,6 +538,9 @@ class NET_EXPORT_PRIVATE QuicStreamFactory
   // Size of the UDP receive buffer.
   int socket_receive_buffer_size_;
 
+  // Set if we do want to delay TCP connection when it is racing with QUIC.
+  bool delay_tcp_race_;
+
   // If more than |yield_after_packets_| packets have been read or more than
   // |yield_after_duration_| time has passed, then
   // QuicChromiumPacketReader::StartReading() yields by doing a PostTask().