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

PiperOrigin-RevId: 269891154
Change-Id: Ic65bba9709fde1dfa6c310ae65c1d31af6401b4b

quic/core/quic_connection.cc

diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index 6f1b4d5..b9f56ee 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -3610,7 +3610,7 @@
   sent_packet_manager_.SetSessionDecideWhatToWrite(
       enable_session_decides_what_to_write);
   if (version().SupportsAntiAmplificationLimit()) {
-    sent_packet_manager_.DisableHandshakeMode();
+    sent_packet_manager_.EnableIetfPtoAndLossDetection();
   }
   packet_generator_.SetCanSetTransmissionType(
       enable_session_decides_what_to_write);

quic/core/quic_sent_packet_manager.cc

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

quic/core/quic_sent_packet_manager.h

diff --git a/quic/core/quic_sent_packet_manager.h b/quic/core/quic_sent_packet_manager.h
index 0199648..352ca31 100644
--- a/quic/core/quic_sent_packet_manager.h
+++ b/quic/core/quic_sent_packet_manager.h
@@ -419,7 +419,8 @@
   void AdjustPendingTimerTransmissions();
 
   // Called to disable HANDSHAKE_MODE, and only PTO and LOSS modes are used.
-  void DisableHandshakeMode();
+  // Also enable IETF loss detection.
+  void EnableIetfPtoAndLossDetection();
 
   bool supports_multiple_packet_number_spaces() const {
     return unacked_packets_.supports_multiple_packet_number_spaces();

quic/core/quic_sent_packet_manager_test.cc

diff --git a/quic/core/quic_sent_packet_manager_test.cc b/quic/core/quic_sent_packet_manager_test.cc
index e787715..4f6412a 100644
--- a/quic/core/quic_sent_packet_manager_test.cc
+++ b/quic/core/quic_sent_packet_manager_test.cc
@@ -3179,7 +3179,7 @@
 TEST_P(QuicSentPacketManagerTest, DisableHandshakeModeClient) {
   QuicSentPacketManagerPeer::SetPerspective(&manager_, Perspective::IS_CLIENT);
   manager_.SetSessionDecideWhatToWrite(true);
-  manager_.DisableHandshakeMode();
+  manager_.EnableIetfPtoAndLossDetection();
   // Send CHLO.
   SendCryptoPacket(1);
   EXPECT_NE(QuicTime::Zero(), manager_.GetRetransmissionTime());
@@ -3202,7 +3202,7 @@
 
 TEST_P(QuicSentPacketManagerTest, DisableHandshakeModeServer) {
   manager_.SetSessionDecideWhatToWrite(true);
-  manager_.DisableHandshakeMode();
+  manager_.EnableIetfPtoAndLossDetection();
   // Send SHLO.
   SendCryptoPacket(1);
   EXPECT_NE(QuicTime::Zero(), manager_.GetRetransmissionTime());