gfe-relnote: Deprecate --gfe2_reloadable_flag_quic_fix_time_of_first_packet_sent_after_receiving.

PiperOrigin-RevId: 254043116
Change-Id: I996b5ddb083660867dad9268afb2e4a120b14f80
diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index 71d3156..bca1ca3 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -304,11 +304,7 @@
                         this),
       idle_network_timeout_(QuicTime::Delta::Infinite()),
       handshake_timeout_(QuicTime::Delta::Infinite()),
-      time_of_first_packet_sent_after_receiving_(
-          GetQuicReloadableFlag(
-              quic_fix_time_of_first_packet_sent_after_receiving)
-              ? QuicTime::Zero()
-              : clock_->ApproximateNow()),
+      time_of_first_packet_sent_after_receiving_(QuicTime::Zero()),
       time_of_last_received_packet_(clock_->ApproximateNow()),
       time_of_previous_received_packet_(QuicTime::Zero()),
       sent_packet_manager_(
@@ -2569,27 +2565,13 @@
       SetPathDegradingAlarm();
     }
 
-    if (GetQuicReloadableFlag(
-            quic_fix_time_of_first_packet_sent_after_receiving)) {
-      // Update |time_of_first_packet_sent_after_receiving_| if this is the
-      // first packet sent after the last packet was received. If it were
-      // updated on every sent packet, then sending into a black hole might
-      // never timeout.
-      if (time_of_first_packet_sent_after_receiving_ <
-          time_of_last_received_packet_) {
-        QUIC_RELOADABLE_FLAG_COUNT(
-            quic_fix_time_of_first_packet_sent_after_receiving);
-        time_of_first_packet_sent_after_receiving_ = packet_send_time;
-      }
-    } else {
-      // Only adjust the last sent time (for the purpose of tracking the idle
-      // timeout) if this is the first retransmittable packet sent after a
-      // packet is received. If it were updated on every sent packet, then
-      // sending into a black hole might never timeout.
-      if (time_of_first_packet_sent_after_receiving_ <=
-          time_of_last_received_packet_) {
-        time_of_first_packet_sent_after_receiving_ = packet_send_time;
-      }
+    // Update |time_of_first_packet_sent_after_receiving_| if this is the
+    // first packet sent after the last packet was received. If it were
+    // updated on every sent packet, then sending into a black hole might
+    // never timeout.
+    if (time_of_first_packet_sent_after_receiving_ <
+        time_of_last_received_packet_) {
+      time_of_first_packet_sent_after_receiving_ = packet_send_time;
     }
   }
 
diff --git a/quic/core/quic_connection_test.cc b/quic/core/quic_connection_test.cc
index 534b6a3..58d84a1 100644
--- a/quic/core/quic_connection_test.cc
+++ b/quic/core/quic_connection_test.cc
@@ -4473,28 +4473,11 @@
   SendStreamDataToPeer(1, "foo", 0, NO_FIN, &last_packet);
   EXPECT_EQ(QuicPacketNumber(2u), last_packet);
 
-  if (GetQuicReloadableFlag(
-          quic_fix_time_of_first_packet_sent_after_receiving)) {
-    // Simulate the timeout alarm firing, the connection will be closed.
-    EXPECT_CALL(visitor_, OnConnectionClosed(QUIC_NETWORK_IDLE_TIMEOUT, _,
-                                             ConnectionCloseSource::FROM_SELF));
-    clock_.AdvanceTime(initial_ddl - clock_.ApproximateNow());
-    connection_.GetTimeoutAlarm()->Fire();
-  } else {
-    // Simulate the timeout alarm firing, the connection will not be closed.
-    EXPECT_CALL(visitor_, OnConnectionClosed(_, _, _)).Times(0);
-    clock_.AdvanceTime(initial_ddl - clock_.ApproximateNow());
-    connection_.GetTimeoutAlarm()->Fire();
-    EXPECT_TRUE(connection_.GetTimeoutAlarm()->IsSet());
-    EXPECT_TRUE(connection_.connected());
-
-    // Advance another 20ms, and fire the alarm again. The connection will be
-    // closed.
-    EXPECT_CALL(visitor_, OnConnectionClosed(QUIC_NETWORK_IDLE_TIMEOUT, _,
-                                             ConnectionCloseSource::FROM_SELF));
-    clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(20));
-    connection_.GetTimeoutAlarm()->Fire();
-  }
+  // Simulate the timeout alarm firing, the connection will be closed.
+  EXPECT_CALL(visitor_, OnConnectionClosed(QUIC_NETWORK_IDLE_TIMEOUT, _,
+                                           ConnectionCloseSource::FROM_SELF));
+  clock_.AdvanceTime(initial_ddl - clock_.ApproximateNow());
+  connection_.GetTimeoutAlarm()->Fire();
 
   EXPECT_FALSE(connection_.GetTimeoutAlarm()->IsSet());
   EXPECT_FALSE(connection_.connected());