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

net/quic/test_tools/quic_stream_factory_peer.h

Index: net/quic/test_tools/quic_stream_factory_peer.h
diff --git a/net/quic/test_tools/quic_stream_factory_peer.h b/net/quic/test_tools/quic_stream_factory_peer.h
index a8ab16e11b550b9488879642baaaeeb4c4f71dff..e0d85a34c64183413ab707f42eb7b0ea1a4cbe9d 100644
--- a/net/quic/test_tools/quic_stream_factory_peer.h
+++ b/net/quic/test_tools/quic_stream_factory_peer.h
@@ -55,6 +55,10 @@ class QuicStreamFactoryPeer {
 
   static bool IsQuicDisabled(QuicStreamFactory* factory, uint16_t port);
 
+  static bool GetDelayTcpRace(QuicStreamFactory* factory);
+
+  static void SetDelayTcpRace(QuicStreamFactory* factory, bool delay_tcp_race);
+
   static void SetYieldAfterPackets(QuicStreamFactory* factory,
                                    int yield_after_packets);