Deprecate --gfe2_reloadable_flag_quic_bbr2_startup_loss_exit_use_max_delivered.

PiperOrigin-RevId: 346093240
Change-Id: I1e7e76bb63200381d115be2f8f08f698784c76a3

quic/core/congestion_control/bbr2_misc.cc

diff --git a/quic/core/congestion_control/bbr2_misc.cc b/quic/core/congestion_control/bbr2_misc.cc
index 3e3937a..62b721a 100644
--- a/quic/core/congestion_control/bbr2_misc.cc
+++ b/quic/core/congestion_control/bbr2_misc.cc
@@ -148,8 +148,7 @@
     loss_events_in_round_++;
   }
 
-  if (GetQuicReloadableFlag(quic_bbr2_startup_loss_exit_use_max_delivered) &&
-      congestion_event->bytes_acked > 0 &&
+  if (congestion_event->bytes_acked > 0 &&
       congestion_event->last_packet_send_state.is_valid &&
       total_bytes_acked() >
           congestion_event->last_packet_send_state.total_bytes_acked) {
@@ -294,9 +293,7 @@
 void Bbr2NetworkModel::RestartRound() {
   bytes_lost_in_round_ = 0;
   loss_events_in_round_ = 0;
-  if (GetQuicReloadableFlag(quic_bbr2_startup_loss_exit_use_max_delivered)) {
-    max_bytes_delivered_in_round_ = 0;
-  }
+  max_bytes_delivered_in_round_ = 0;
   round_trip_counter_.RestartRound();
 }
 

quic/core/congestion_control/bbr2_sender.cc

diff --git a/quic/core/congestion_control/bbr2_sender.cc b/quic/core/congestion_control/bbr2_sender.cc
index 5d672d1..a71dbdf 100644
--- a/quic/core/congestion_control/bbr2_sender.cc
+++ b/quic/core/congestion_control/bbr2_sender.cc
@@ -137,12 +137,10 @@
   if (ContainsQuicTag(connection_options, kB2NE)) {
     params_.always_exit_startup_on_excess_loss = false;
   }
-  if (GetQuicReloadableFlag(quic_bbr2_startup_loss_exit_use_max_delivered) &&
-      ContainsQuicTag(connection_options, kB2SL)) {
+  if (ContainsQuicTag(connection_options, kB2SL)) {
     params_.startup_loss_exit_use_max_delivered_for_inflight_hi = false;
   }
-  if (GetQuicReloadableFlag(quic_bbr2_startup_loss_exit_use_max_delivered) &&
-      ContainsQuicTag(connection_options, kB2H2)) {
+  if (ContainsQuicTag(connection_options, kB2H2)) {
     params_.limit_inflight_hi_by_max_delivered = true;
   }
   if (GetQuicReloadableFlag(quic_bbr2_use_bytes_delivered) &&

quic/core/congestion_control/bbr2_simulator_test.cc

diff --git a/quic/core/congestion_control/bbr2_simulator_test.cc b/quic/core/congestion_control/bbr2_simulator_test.cc
index ec7eeeb..5aec9cb 100644
--- a/quic/core/congestion_control/bbr2_simulator_test.cc
+++ b/quic/core/congestion_control/bbr2_simulator_test.cc
@@ -732,7 +732,6 @@
 
 // Test exiting STARTUP earlier upon loss due to loss.
 TEST_F(Bbr2DefaultTopologyTest, ExitStartupDueToLoss) {
-  SetQuicReloadableFlag(quic_bbr2_startup_loss_exit_use_max_delivered, true);
   DefaultTopologyParams params;
   params.switch_queue_capacity_in_bdp = 0.5;
   CreateNetwork(params);
@@ -765,7 +764,6 @@
 // Test exiting STARTUP earlier upon loss due to loss when connection option
 // B2SL is used.
 TEST_F(Bbr2DefaultTopologyTest, ExitStartupDueToLossB2SL) {
-  SetQuicReloadableFlag(quic_bbr2_startup_loss_exit_use_max_delivered, true);
   SetConnectionOption(kB2SL);
   DefaultTopologyParams params;
   params.switch_queue_capacity_in_bdp = 0.5;

quic/core/congestion_control/bbr2_startup.cc

diff --git a/quic/core/congestion_control/bbr2_startup.cc b/quic/core/congestion_control/bbr2_startup.cc
index eb0dc08..479c66b 100644
--- a/quic/core/congestion_control/bbr2_startup.cc
+++ b/quic/core/congestion_control/bbr2_startup.cc
@@ -110,12 +110,7 @@
     QuicByteCount new_inflight_hi = model_->BDP();
     if (Params().startup_loss_exit_use_max_delivered_for_inflight_hi) {
       if (new_inflight_hi < model_->max_bytes_delivered_in_round()) {
-        QUIC_RELOADABLE_FLAG_COUNT_N(
-            quic_bbr2_startup_loss_exit_use_max_delivered, 1, 2);
         new_inflight_hi = model_->max_bytes_delivered_in_round();
-      } else {
-        QUIC_RELOADABLE_FLAG_COUNT_N(
-            quic_bbr2_startup_loss_exit_use_max_delivered, 2, 2);
       }
     }
     QUIC_DVLOG(3) << sender_ << " Exiting STARTUP due to loss. inflight_hi:"

quic/core/quic_flags_list.h

diff --git a/quic/core/quic_flags_list.h b/quic/core/quic_flags_list.h
index 4814f41..ef27e46 100644
--- a/quic/core/quic_flags_list.h
+++ b/quic/core/quic_flags_list.h
@@ -13,7 +13,6 @@
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_bbr2_avoid_too_low_probe_bw_cwnd, false)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_bbr2_disable_reno_coexistence, false)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_bbr2_fewer_startup_round_trips, false)
-QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_bbr2_startup_loss_exit_use_max_delivered, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_bbr2_use_bytes_delivered, false)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_can_send_ack_frequency, true)
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_conservative_bursts, false)