Add a time based loss detection algorithm to QUIC that loses packets

net/quic/quic_sent_packet_manager.cc

Index: net/quic/quic_sent_packet_manager.cc
diff --git a/net/quic/quic_sent_packet_manager.cc b/net/quic/quic_sent_packet_manager.cc
index ad83057217a17e8f2f3ab7caa674a890c66d30e6..9ac7210031e9dc39fbf7c29c1287a8f34e057b91 100644
--- a/net/quic/quic_sent_packet_manager.cc
+++ b/net/quic/quic_sent_packet_manager.cc
@@ -399,9 +399,10 @@ bool QuicSentPacketManager::OnPacketSent(
 
 void QuicSentPacketManager::OnRetransmissionTimeout() {
   DCHECK(unacked_packets_.HasPendingPackets());
-  // Handshake retransmission, TLP, and RTO are implemented with a single alarm.
-  // The handshake alarm is set when the handshake has not completed, and the
-  // TLP and RTO alarms are set after that.
+  // Handshake retransmission, timer based loss detection, TLP, and RTO are
+  // implemented with a single alarm. The handshake alarm is set when the
+  // handshake has not completed, the loss alarm is set when the loss detection
+  // algorithm says to, and the TLP and  RTO alarms are set after that.
   // The TLP alarm is always set to run for under an RTO.
   switch (GetRetransmissionMode()) {
     case HANDSHAKE_MODE:
@@ -409,6 +410,7 @@ void QuicSentPacketManager::OnRetransmissionTimeout() {
       RetransmitCryptoPackets();
       return;
     case LOSS_MODE:
+      ++stats_->loss_timeout_count;
       InvokeLossDetection(clock_->Now());
       return;
     case TLP_MODE:
@@ -560,7 +562,8 @@ void QuicSentPacketManager::InvokeLossDetection(QuicTime time) {
       loss_algorithm_->DetectLostPackets(unacked_packets_,
                                          time,
                                          largest_observed_,
-                                         send_algorithm_->SmoothedRtt());
+                                         send_algorithm_->SmoothedRtt(),
+                                         rtt_sample_);
   for (SequenceNumberSet::const_iterator it = lost_packets.begin();
        it != lost_packets.end(); ++it) {
     QuicPacketSequenceNumber sequence_number = *it;