Deprecate --gfe2_reloadable_flag_quic_bbr2_startup_extra_acked.

PiperOrigin-RevId: 476089535

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 4abe297..b9d60db 100644
--- a/quiche/quic/core/congestion_control/bbr2_sender.cc
+++ b/quiche/quic/core/congestion_control/bbr2_sender.cc
@@ -179,14 +179,10 @@
   if (ContainsQuicTag(connection_options, kB203)) {
     params_.probe_up_ignore_inflight_hi = true;
   }
-  if (GetQuicReloadableFlag(quic_bbr2_startup_extra_acked) &&
-      ContainsQuicTag(connection_options, kB204)) {
-    QUIC_RELOADABLE_FLAG_COUNT_N(quic_bbr2_startup_extra_acked, 1, 2);
+  if (ContainsQuicTag(connection_options, kB204)) {
     model_.SetReduceExtraAckedOnBandwidthIncrease(true);
   }
-  if (GetQuicReloadableFlag(quic_bbr2_startup_extra_acked) &&
-      ContainsQuicTag(connection_options, kB205)) {
-    QUIC_RELOADABLE_FLAG_COUNT_N(quic_bbr2_startup_extra_acked, 2, 2);
+  if (ContainsQuicTag(connection_options, kB205)) {
     params_.startup_include_extra_acked = true;
   }
   if (ContainsQuicTag(connection_options, kB207)) {

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 056dcb7..9c0d106 100644
--- a/quiche/quic/core/congestion_control/bbr2_simulator_test.cc
+++ b/quiche/quic/core/congestion_control/bbr2_simulator_test.cc
@@ -415,7 +415,6 @@
 
 // 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);
   SetConnectionOption(kB205);
   SetConnectionOption(kB207);
   DefaultTopologyParams params;
@@ -1004,7 +1003,6 @@
 
 // Test Bbr2's reaction to a 100x bandwidth increase during a transfer with B204
 TEST_F(Bbr2DefaultTopologyTest, QUIC_SLOW_TEST(BandwidthIncreaseB204)) {
-  SetQuicReloadableFlag(quic_bbr2_startup_extra_acked, true);
   SetConnectionOption(kB204);
   DefaultTopologyParams params;
   params.local_link.bandwidth = QuicBandwidth::FromKBitsPerSecond(15000);
@@ -1039,7 +1037,6 @@
 // in the presence of ACK aggregation.
 TEST_F(Bbr2DefaultTopologyTest,
        QUIC_SLOW_TEST(BandwidthIncreaseB204Aggregation)) {
-  SetQuicReloadableFlag(quic_bbr2_startup_extra_acked, true);
   SetConnectionOption(kB204);
   DefaultTopologyParams params;
   params.local_link.bandwidth = QuicBandwidth::FromKBitsPerSecond(15000);
@@ -1079,7 +1076,6 @@
 
 // Test Bbr2's reaction to a 100x bandwidth increase during a transfer with B205
 TEST_F(Bbr2DefaultTopologyTest, QUIC_SLOW_TEST(BandwidthIncreaseB205)) {
-  SetQuicReloadableFlag(quic_bbr2_startup_extra_acked, true);
   SetConnectionOption(kB205);
   DefaultTopologyParams params;
   params.local_link.bandwidth = QuicBandwidth::FromKBitsPerSecond(15000);
@@ -1113,7 +1109,6 @@
 // in the presence of ACK aggregation.
 TEST_F(Bbr2DefaultTopologyTest,
        QUIC_SLOW_TEST(BandwidthIncreaseB205Aggregation)) {
-  SetQuicReloadableFlag(quic_bbr2_startup_extra_acked, true);
   SetConnectionOption(kB205);
   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 0979687..2122bc4 100644
--- a/quiche/quic/core/quic_flags_list.h
+++ b/quiche/quic/core/quic_flags_list.h
@@ -97,8 +97,6 @@
 QUIC_FLAG(quic_reloadable_flag_quic_unified_iw_options, true)
 // When true, support draft-ietf-quic-v2-01
 QUIC_FLAG(quic_reloadable_flag_quic_enable_version_2_draft_01, false)
-// 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 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)