Deprecate quic_randomize_transport_parameter_order

This CL deprecates gfe2_reloadable_flag_quic_randomize_transport_parameter_order.

PiperOrigin-RevId: 400806481
diff --git a/quic/core/crypto/transport_parameters.cc b/quic/core/crypto/transport_parameters.cc
index 4011769..75d4323 100644
--- a/quic/core/crypto/transport_parameters.cc
+++ b/quic/core/crypto/transport_parameters.cc
@@ -741,14 +741,11 @@
     parameter_ids.push_back(kv.first);
   }
 
-  if (GetQuicReloadableFlag(quic_randomize_transport_parameter_order)) {
-    QUIC_RELOADABLE_FLAG_COUNT(quic_randomize_transport_parameter_order);
-    // Randomize order of sent transport parameters by walking the array
-    // backwards and swapping each element with a random earlier one.
-    for (size_t i = parameter_ids.size() - 1; i > 0; i--) {
-      std::swap(parameter_ids[i],
-                parameter_ids[random->InsecureRandUint64() % (i + 1)]);
-    }
+  // Randomize order of sent transport parameters by walking the array
+  // backwards and swapping each element with a random earlier one.
+  for (size_t i = parameter_ids.size() - 1; i > 0; i--) {
+    std::swap(parameter_ids[i],
+              parameter_ids[random->InsecureRandUint64() % (i + 1)]);
   }
 
   out->resize(max_transport_param_length);
diff --git a/quic/core/crypto/transport_parameters_test.cc b/quic/core/crypto/transport_parameters_test.cc
index ffeb4aa..48af1c4 100644
--- a/quic/core/crypto/transport_parameters_test.cc
+++ b/quic/core/crypto/transport_parameters_test.cc
@@ -933,7 +933,6 @@
 }
 
 TEST_P(TransportParametersTest, SerializationOrderIsRandom) {
-  SetQuicReloadableFlag(quic_randomize_transport_parameter_order, true);
   TransportParameters orig_params;
   orig_params.perspective = Perspective::IS_CLIENT;
   orig_params.version = kFakeVersionLabel;
diff --git a/quic/core/quic_flags_list.h b/quic/core/quic_flags_list.h
index f1784a0..205ac02 100644
--- a/quic/core/quic_flags_list.h
+++ b/quic/core/quic_flags_list.h
@@ -127,8 +127,6 @@
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_default_to_bbr, false)
 // When true, prevents QUIC\'s PacingSender from generating bursts when the congestion controller is CWND limited and not pacing limited.
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_fix_pacing_sender_bursts, false)
-// When true, randomizes the order of sent transport parameters in QUIC+TLS.
-QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_randomize_transport_parameter_order, true)
 // When true, set the initial congestion control window from connection options in QuicSentPacketManager rather than TcpCubicSenderBytes.
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_unified_iw_options, true)
 // When true, the B203 connection option causes the Bbr2Sender to ignore inflight_hi during PROBE_UP and increase it when the bytes delivered without loss are higher.