Fix a bug protected by gfe2_reloadable_flag_quic_respect_send_alarm where acks would not be sent im…

net/quic/congestion_control/tcp_cubic_bytes_sender.cc

 // Copyright (c) 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/congestion_control/tcp_cubic_bytes_sender.h"
 
 #include <algorithm>
 
 #include "net/quic/congestion_control/prr_sender.h"
 #include "net/quic/congestion_control/rtt_stats.h"
@@ skipping 200 matching lines @@
   largest_sent_packet_number_ = packet_number;
   hybrid_slow_start_.OnPacketSent(packet_number);
   return true;
 }
 
 QuicTime::Delta TcpCubicBytesSender::TimeUntilSend(
     QuicTime /* now */,
     QuicByteCount bytes_in_flight,
     HasRetransmittableData has_retransmittable_data) const {
   if (has_retransmittable_data == NO_RETRANSMITTABLE_DATA) {
+    DCHECK(!FLAGS_quic_respect_send_alarm2);
     // For TCP we can always send an ACK immediately.
     return QuicTime::Delta::Zero();
   }
   if (InRecovery()) {
     // PRR is used when in recovery.
     return prr_.TimeUntilSend(GetCongestionWindow(), bytes_in_flight,
                               slowstart_threshold_);
   }
   if (GetCongestionWindow() > bytes_in_flight) {
     return QuicTime::Delta::Zero();
@@ skipping 132 matching lines @@
   largest_sent_packet_number_ = 0;
   largest_acked_packet_number_ = 0;
   largest_sent_at_last_cutback_ = 0;
   congestion_window_ = initial_tcp_congestion_window_;
   max_congestion_window_ = initial_max_tcp_congestion_window_;
   slowstart_threshold_ = initial_max_tcp_congestion_window_;
   last_cutback_exited_slowstart_ = false;
 }
 
 }  // namespace net