Deprecate gfe2_reloadable_flag_quic_donot_rearm_pto_on_application_data_during_handshake.

PiperOrigin-RevId: 428518430

quic/core/quic_connection.cc

diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index 974e192..254f33a 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -3725,15 +3725,8 @@
       return true;
     }
   }
-  if (GetQuicReloadableFlag(
-          quic_donot_rearm_pto_on_application_data_during_handshake)) {
-    QUIC_RELOADABLE_FLAG_COUNT(
-        quic_donot_rearm_pto_on_application_data_during_handshake);
-    if (ShouldSetRetransmissionAlarmOnPacketSent(in_flight,
-                                                 packet->encryption_level)) {
-      SetRetransmissionAlarm();
-    }
-  } else if (in_flight || !retransmission_alarm_->IsSet()) {
+  if (ShouldSetRetransmissionAlarmOnPacketSent(in_flight,
+                                               packet->encryption_level)) {
     SetRetransmissionAlarm();
   }
   SetPingAlarm();

quic/core/quic_connection_test.cc

diff --git a/quic/core/quic_connection_test.cc b/quic/core/quic_connection_test.cc
index 0969070..de59528 100644
--- a/quic/core/quic_connection_test.cc
+++ b/quic/core/quic_connection_test.cc
@@ -14933,14 +14933,8 @@
   connection_.SetDefaultEncryptionLevel(ENCRYPTION_ZERO_RTT);
   connection_.SendStreamDataWithString(2, "foo", 0, NO_FIN);
   ASSERT_TRUE(connection_.GetRetransmissionAlarm()->IsSet());
-  if (GetQuicReloadableFlag(
-          quic_donot_rearm_pto_on_application_data_during_handshake)) {
-    // PTO deadline should be unchanged.
-    EXPECT_EQ(pto_deadline, connection_.GetRetransmissionAlarm()->deadline());
-  } else {
-    // PTO gets re-armed.
-    EXPECT_NE(pto_deadline, connection_.GetRetransmissionAlarm()->deadline());
-  }
+  // PTO deadline should be unchanged.
+  EXPECT_EQ(pto_deadline, connection_.GetRetransmissionAlarm()->deadline());
 }
 
 TEST_P(QuicConnectionTest, QueueingUndecryptablePacketsDoesntPostponePTO) {

quic/core/quic_flags_list.h

diff --git a/quic/core/quic_flags_list.h b/quic/core/quic_flags_list.h
index fe5bcd5..2e7b263 100644
--- a/quic/core/quic_flags_list.h
+++ b/quic/core/quic_flags_list.h
@@ -71,8 +71,6 @@
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_tls_no_select_cert_if_disconnected, true)
 // If true, do not count bytes sent/received on the alternative path into the bytes sent/received on the default path.
 QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_count_bytes_on_alternative_path_seperately, true)
-// If true, do not re-arm PTO while sending application data during handshake.
-QUIC_FLAG(FLAGS_quic_reloadable_flag_quic_donot_rearm_pto_on_application_data_during_handshake, true)
 // If true, do not use the gQUIC common certificate set for certificate compression.
 QUIC_FLAG(FLAGS_quic_restart_flag_quic_no_common_cert_set, true)
 // If true, drop unsent PATH_RESPONSEs and rely on peer\'s retry.