Deprecate --gfe2_reloadable_flag_quic_check_retire_cid_with_next_cid_sequence_number

PiperOrigin-RevId: 551525233

quiche/quic/core/quic_connection_id_manager.cc

diff --git a/quiche/quic/core/quic_connection_id_manager.cc b/quiche/quic/core/quic_connection_id_manager.cc
index e192880..c4bf3ee 100644
--- a/quiche/quic/core/quic_connection_id_manager.cc
+++ b/quiche/quic/core/quic_connection_id_manager.cc
@@ -329,19 +329,9 @@
     const QuicRetireConnectionIdFrame& frame, QuicTime::Delta pto_delay,
     std::string* error_detail) {
   QUICHE_DCHECK(!active_connection_ids_.empty());
-  if (GetQuicReloadableFlag(
-          quic_check_retire_cid_with_next_cid_sequence_number)) {
-    QUIC_RELOADABLE_FLAG_COUNT(
-        quic_check_retire_cid_with_next_cid_sequence_number);
-    if (frame.sequence_number >= next_connection_id_sequence_number_) {
-      *error_detail = "To be retired connecton ID is never issued.";
-      return IETF_QUIC_PROTOCOL_VIOLATION;
-    }
-  } else {
-    if (frame.sequence_number > active_connection_ids_.back().second) {
-      *error_detail = "To be retired connecton ID is never issued.";
-      return IETF_QUIC_PROTOCOL_VIOLATION;
-    }
+  if (frame.sequence_number >= next_connection_id_sequence_number_) {
+    *error_detail = "To be retired connecton ID is never issued.";
+    return IETF_QUIC_PROTOCOL_VIOLATION;
   }
 
   auto it =

quiche/quic/core/quic_connection_id_manager_test.cc

diff --git a/quiche/quic/core/quic_connection_id_manager_test.cc b/quiche/quic/core/quic_connection_id_manager_test.cc
index 137be15..f694cb0 100644
--- a/quiche/quic/core/quic_connection_id_manager_test.cc
+++ b/quiche/quic/core/quic_connection_id_manager_test.cc
@@ -1046,19 +1046,11 @@
       QUIC_NO_ERROR)
       << error_details;
 
-  if (GetQuicReloadableFlag(
-          quic_check_retire_cid_with_next_cid_sequence_number)) {
-    EXPECT_EQ(
-        cid_manager_.OnRetireConnectionIdFrame(
-            retire_cid_frame, QuicTime::Delta::FromSeconds(1), &error_details),
-        QUIC_NO_ERROR)
-        << error_details;
-  } else {
-    EXPECT_EQ(
-        cid_manager_.OnRetireConnectionIdFrame(
-            retire_cid_frame, QuicTime::Delta::FromSeconds(1), &error_details),
-        IETF_QUIC_PROTOCOL_VIOLATION);
-  }
+  EXPECT_EQ(
+      cid_manager_.OnRetireConnectionIdFrame(
+          retire_cid_frame, QuicTime::Delta::FromSeconds(1), &error_details),
+      QUIC_NO_ERROR)
+      << error_details;
 }
 
 }  // namespace

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 9cdfe3d..34274d3 100644
--- a/quiche/quic/core/quic_flags_list.h
+++ b/quiche/quic/core/quic_flags_list.h
@@ -83,8 +83,6 @@
 QUIC_FLAG(quic_reloadable_flag_quic_default_to_bbr_v2, false)
 // If true, use a LRU cache to record client addresses of packets received on server\'s original address.
 QUIC_FLAG(quic_reloadable_flag_quic_use_received_client_addresses_cache, true)
-// If true, use next_connection_id_sequence_number to validate retired cid number.
-QUIC_FLAG(quic_reloadable_flag_quic_check_retire_cid_with_next_cid_sequence_number, true)
 // If true, uses conservative cwnd gain and pacing gain when cwnd gets bootstrapped.
 QUIC_FLAG(quic_reloadable_flag_quic_conservative_cwnd_and_pacing_gains, false)
 // If true, when TicketCrypter fails to encrypt a session ticket, quic::TlsServerHandshaker will send a placeholder ticket, instead of an empty one, to the client.