gfe-relnote: Use IETF loss detection for T099. Not used in prod, not protected.

PiperOrigin-RevId: 269891154
Change-Id: Ic65bba9709fde1dfa6c310ae65c1d31af6401b4b
diff --git a/quic/core/quic_sent_packet_manager.cc b/quic/core/quic_sent_packet_manager.cc
index 8731306..132eb0a 100644
--- a/quic/core/quic_sent_packet_manager.cc
+++ b/quic/core/quic_sent_packet_manager.cc
@@ -970,11 +970,12 @@
   pending_timer_transmission_count_ = 1;
 }
 
-void QuicSentPacketManager::DisableHandshakeMode() {
+void QuicSentPacketManager::EnableIetfPtoAndLossDetection() {
   DCHECK(session_decides_what_to_write());
   fix_rto_retransmission_ = true;
   pto_enabled_ = true;
   handshake_mode_disabled_ = true;
+  uber_loss_algorithm_.SetLossDetectionType(kIetfLossDetection);
 }
 
 QuicSentPacketManager::RetransmissionTimeoutMode