Deprecate --gfe2_reloadable_flag_quic_bbr2_no_probe_up_exit_if_no_queue.

PiperOrigin-RevId: 477268329

quiche/quic/core/congestion_control/bbr2_probe_bw.cc

diff --git a/quiche/quic/core/congestion_control/bbr2_probe_bw.cc b/quiche/quic/core/congestion_control/bbr2_probe_bw.cc
index a06b7d1..88e87b6 100644
--- a/quiche/quic/core/congestion_control/bbr2_probe_bw.cc
+++ b/quiche/quic/core/congestion_control/bbr2_probe_bw.cc
@@ -202,8 +202,6 @@
         if (send_state.is_app_limited) {
           // If there's excess loss or a queue is building, exit even if the
           // last sample was app limited.
-          QUIC_RELOADABLE_FLAG_COUNT_N(quic_bbr2_no_probe_up_exit_if_no_queue,
-                                       2, 2);
         }
         const QuicByteCount inflight_target =
             sender_->GetTargetBytesInflight() * (1.0 - Params().beta);
@@ -483,8 +481,6 @@
     //   HasPhaseLasted(model_->MinRtt(), congestion_event)
   } else if (cycle_.rounds_in_phase > 0) {
     if (Params().probe_up_dont_exit_if_no_queue_) {
-      QUIC_RELOADABLE_FLAG_COUNT_N(quic_bbr2_no_probe_up_exit_if_no_queue, 1,
-                                   2);
       is_queuing = congestion_event.end_of_round_trip &&
                    model_->CheckPersistentQueue(
                        congestion_event, Params().probe_bw_probe_inflight_gain);

quiche/quic/core/congestion_control/bbr2_sender.cc

diff --git a/quiche/quic/core/congestion_control/bbr2_sender.cc b/quiche/quic/core/congestion_control/bbr2_sender.cc
index b9d60db..880ea35 100644
--- a/quiche/quic/core/congestion_control/bbr2_sender.cc
+++ b/quiche/quic/core/congestion_control/bbr2_sender.cc
@@ -172,8 +172,7 @@
   if (ContainsQuicTag(connection_options, kB201)) {
     params_.probe_bw_check_cwnd_limited_before_aggregation_epoch = true;
   }
-  if (GetQuicReloadableFlag(quic_bbr2_no_probe_up_exit_if_no_queue) &&
-      ContainsQuicTag(connection_options, kB202)) {
+  if (ContainsQuicTag(connection_options, kB202)) {
     params_.probe_up_dont_exit_if_no_queue_ = true;
   }
   if (ContainsQuicTag(connection_options, kB203)) {

quiche/quic/core/congestion_control/bbr2_simulator_test.cc

diff --git a/quiche/quic/core/congestion_control/bbr2_simulator_test.cc b/quiche/quic/core/congestion_control/bbr2_simulator_test.cc
index 8dce6bd..f807f02 100644
--- a/quiche/quic/core/congestion_control/bbr2_simulator_test.cc
+++ b/quiche/quic/core/congestion_control/bbr2_simulator_test.cc
@@ -853,7 +853,6 @@
 
 // Test Bbr2's reaction to a 100x bandwidth increase during a transfer with B202
 TEST_F(Bbr2DefaultTopologyTest, QUIC_SLOW_TEST(BandwidthIncreaseB202)) {
-  SetQuicReloadableFlag(quic_bbr2_no_probe_up_exit_if_no_queue, true);
   SetConnectionOption(kB202);
   DefaultTopologyParams params;
   params.local_link.bandwidth = QuicBandwidth::FromKBitsPerSecond(15000);
@@ -887,7 +886,6 @@
 // in the presence of ACK aggregation.
 TEST_F(Bbr2DefaultTopologyTest,
        QUIC_SLOW_TEST(BandwidthIncreaseB202Aggregation)) {
-  SetQuicReloadableFlag(quic_bbr2_no_probe_up_exit_if_no_queue, true);
   SetConnectionOption(kB202);
   DefaultTopologyParams params;
   params.local_link.bandwidth = QuicBandwidth::FromKBitsPerSecond(15000);

quiche/quic/core/quic_flags_list.h

diff --git a/quiche/quic/core/quic_flags_list.h b/quiche/quic/core/quic_flags_list.h
index 908286b..9363f9c 100644
--- a/quiche/quic/core/quic_flags_list.h
+++ b/quiche/quic/core/quic_flags_list.h
@@ -17,8 +17,6 @@
 QUIC_FLAG(quic_restart_flag_quic_testonly_default_false, false)
 // A testonly restart flag that will always default to true.
 QUIC_FLAG(quic_restart_flag_quic_testonly_default_true, true)
-// If bytes in flight has dipped below 1.25*MaxBW in the last round, do not exit PROBE_UP due to excess queue buildup.
-QUIC_FLAG(quic_reloadable_flag_quic_bbr2_no_probe_up_exit_if_no_queue, true)
 // If trrue, early return before write control frame in OnCanWrite() if the connection is already closed.
 QUIC_FLAG(quic_reloadable_flag_quic_no_write_control_frame_upon_connection_close, true)
 // If true, QUIC Legacy Version Encapsulation will be disabled.