Deprecate --gfe2_reloadable_flag_quic_bbr2_exit_startup_on_persistent_queue2.

PiperOrigin-RevId: 475839789

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 35bfe44..2ea2f8d 100644
--- a/quiche/quic/core/congestion_control/bbr2_sender.cc
+++ b/quiche/quic/core/congestion_control/bbr2_sender.cc
@@ -191,8 +191,7 @@
     QUIC_RELOADABLE_FLAG_COUNT_N(quic_bbr2_startup_extra_acked, 2, 2);
     params_.startup_include_extra_acked = true;
   }
-  if (GetQuicReloadableFlag(quic_bbr2_exit_startup_on_persistent_queue2) &&
-      ContainsQuicTag(connection_options, kB207)) {
+  if (ContainsQuicTag(connection_options, kB207)) {
     params_.exit_startup_on_persistent_queue = true;
   }
 

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 06a9876..a17dd56 100644
--- a/quiche/quic/core/congestion_control/bbr2_simulator_test.cc
+++ b/quiche/quic/core/congestion_control/bbr2_simulator_test.cc
@@ -385,7 +385,6 @@
 }
 
 TEST_F(Bbr2DefaultTopologyTest, NormalStartupB207) {
-  SetQuicReloadableFlag(quic_bbr2_exit_startup_on_persistent_queue2, true);
   SetConnectionOption(kB207);
   DefaultTopologyParams params;
   CreateNetwork(params);
@@ -417,7 +416,6 @@
 // Add extra_acked to CWND in STARTUP and exit STARTUP on a persistent queue.
 TEST_F(Bbr2DefaultTopologyTest, NormalStartupB207andB205) {
   SetQuicReloadableFlag(quic_bbr2_startup_extra_acked, true);
-  SetQuicReloadableFlag(quic_bbr2_exit_startup_on_persistent_queue2, true);
   SetConnectionOption(kB205);
   SetConnectionOption(kB207);
   DefaultTopologyParams params;
@@ -538,7 +536,6 @@
 }
 
 TEST_F(Bbr2DefaultTopologyTest, SimpleTransferB207) {
-  SetQuicReloadableFlag(quic_bbr2_exit_startup_on_persistent_queue2, true);
   SetConnectionOption(kB207);
   DefaultTopologyParams params;
   CreateNetwork(params);

quiche/quic/core/congestion_control/bbr2_startup.cc

diff --git a/quiche/quic/core/congestion_control/bbr2_startup.cc b/quiche/quic/core/congestion_control/bbr2_startup.cc
index 6910cb0..addf64b 100644
--- a/quiche/quic/core/congestion_control/bbr2_startup.cc
+++ b/quiche/quic/core/congestion_control/bbr2_startup.cc
@@ -54,7 +54,6 @@
   }
   bool has_bandwidth_growth = model_->HasBandwidthGrowth(congestion_event);
   if (Params().exit_startup_on_persistent_queue && !has_bandwidth_growth) {
-    QUIC_RELOADABLE_FLAG_COUNT(quic_bbr2_exit_startup_on_persistent_queue2);
     model_->CheckPersistentQueue(congestion_event, Params().startup_cwnd_gain);
   }
   // TCP BBR always exits upon excessive losses. QUIC BBRv1 does not exit

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 4ba71d6..0a09a9c 100644
--- a/quiche/quic/core/quic_flags_list.h
+++ b/quiche/quic/core/quic_flags_list.h
@@ -101,8 +101,6 @@
 QUIC_FLAG(quic_reloadable_flag_quic_bbr2_ignore_inflight_hi_in_probe_up, true)
 // When true, the B205 connection option enables extra acked in STARTUP, and B204 adds new logic to decrease it whenever max bandwidth increases.
 QUIC_FLAG(quic_reloadable_flag_quic_bbr2_startup_extra_acked, true)
-// When true, the B207 connection option causes BBR2 to exit STARTUP if a persistent queue of 2*BDP has existed for the entire round.
-QUIC_FLAG(quic_reloadable_flag_quic_bbr2_exit_startup_on_persistent_queue2, true)
 // When true, the BBR4 copt sets the extra_acked window to 20 RTTs and BBR5 sets it to 40 RTTs.
 QUIC_FLAG(quic_reloadable_flag_quic_bbr2_extra_acked_window, true)