Deprecate --gfe2_reloadable_flag_quic_match_ietf_reset_code

PiperOrigin-RevId: 428764091

quic/core/quic_flags_list.h

diff --git a/quic/core/quic_flags_list.h b/quic/core/quic_flags_list.h
index fd29e1f..069ba10 100644
--- a/quic/core/quic_flags_list.h
+++ b/quic/core/quic_flags_list.h
@@ -115,8 +115,6 @@
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_server_reverse_validate_new_path3, true)
 // If true, when client attempts TLS resumption, use token in session_cache_ instead of cached_states_ in QuicCryptoClientConfig.
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_tls_use_token_in_session_cache, true)
-// When receiving STOP_SENDING, send a RESET_STREAM with a matching error code.
-QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_match_ietf_reset_code, true)
 // When the flag is true, exit STARTUP after the same number of loss events as PROBE_UP.
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_bbr2_startup_probe_up_loss_events, true)
 // When true, QUIC will both send and validate the version_information transport parameter.

quic/core/quic_stream.cc

diff --git a/quic/core/quic_stream.cc b/quic/core/quic_stream.cc
index f055bdf..6237dae 100644
--- a/quic/core/quic_stream.cc
+++ b/quic/core/quic_stream.cc
@@ -506,13 +506,7 @@
   }
 
   stream_error_ = error;
-  if (GetQuicReloadableFlag(quic_match_ietf_reset_code)) {
-    QUIC_RELOADABLE_FLAG_COUNT(quic_match_ietf_reset_code);
-    MaybeSendRstStream(error);
-  } else {
-    MaybeSendRstStream(
-        QuicResetStreamError::FromInternal(error.internal_code()));
-  }
+  MaybeSendRstStream(error);
   return true;
 }