Remove FEC from send path.

net/quic/quic_connection.cc

Index: net/quic/quic_connection.cc
diff --git a/net/quic/quic_connection.cc b/net/quic/quic_connection.cc
index 75640a3fd9dd6a3658b6d6b4d3928a9883c32fb3..af10c61c320a73a53c2559bdafad6db7de81dbd2 100644
--- a/net/quic/quic_connection.cc
+++ b/net/quic/quic_connection.cc
@@ -188,23 +188,6 @@ class MtuDiscoveryAlarm : public QuicAlarm::Delegate {
   DISALLOW_COPY_AND_ASSIGN(MtuDiscoveryAlarm);
 };
 
-// This alarm may be scheduled when an FEC protected packet is sent out.
-class FecAlarm : public QuicAlarm::Delegate {
- public:
-  explicit FecAlarm(QuicPacketGenerator* packet_generator)
-      : packet_generator_(packet_generator) {}
-
-  QuicTime OnAlarm() override {
-    packet_generator_->OnFecTimeout();
-    return QuicTime::Zero();
-  }
-
- private:
-  QuicPacketGenerator* packet_generator_;
-
-  DISALLOW_COPY_AND_ASSIGN(FecAlarm);
-};
-
 // Listens for acks of MTU discovery packets and raises the maximum packet size
 // of the connection if the probe succeeds.
 class MtuDiscoveryAckListener : public QuicAckListenerInterface {
@@ -304,8 +287,6 @@ QuicConnection::QuicConnection(QuicConnectionId connection_id,
                         random_generator_,
                         helper->GetBufferAllocator(),
                         this),
-      fec_alarm_(helper->CreateAlarm(arena_.New<FecAlarm>(&packet_generator_),
-                                     &arena_)),
       idle_network_timeout_(QuicTime::Delta::Infinite()),
       handshake_timeout_(QuicTime::Delta::Infinite()),
       time_of_last_received_packet_(clock_->ApproximateNow()),
@@ -397,16 +378,6 @@ void QuicConnection::SetFromConfig(const QuicConfig& config) {
   }
   max_undecryptable_packets_ = config.max_undecryptable_packets();
 
-  if (config.HasClientSentConnectionOption(kFSPA, perspective_)) {
-    packet_generator_.set_fec_send_policy(FecSendPolicy::FEC_ALARM_TRIGGER);
-  }
-  if (config.HasClientSentConnectionOption(kFRTT, perspective_)) {
-    // TODO(rtenneti): Delete this code after the 0.25 RTT FEC experiment.
-    const float kFecTimeoutRttMultiplier = 0.25;
-    packet_generator_.set_rtt_multiplier_for_fec_timeout(
-        kFecTimeoutRttMultiplier);
-  }
-
   if (config.HasClientSentConnectionOption(kMTUH, perspective_)) {
     SetMtuDiscoveryTarget(kMtuDiscoveryTargetPacketSizeHigh);
   }
@@ -476,17 +447,6 @@ void QuicConnection::OnError(QuicFramer* framer) {
   SendConnectionCloseWithDetails(framer->error(), framer->detailed_error());
 }
 
-void QuicConnection::MaybeSetFecAlarm(QuicPacketNumber packet_number) {
-  if (fec_alarm_->IsSet()) {
-    return;
-  }
-  QuicTime::Delta timeout = packet_generator_.GetFecTimeout(packet_number);
-  if (!timeout.IsInfinite()) {
-    fec_alarm_->Update(clock_->ApproximateNow().Add(timeout),
-                       QuicTime::Delta::FromMilliseconds(1));
-  }
-}
-
 void QuicConnection::OnPacket() {
   last_packet_decrypted_ = false;
   last_packet_revived_ = false;
@@ -1182,7 +1142,6 @@ QuicConsumedData QuicConnection::SendStreamData(
     QuicIOVector iov,
     QuicStreamOffset offset,
     bool fin,
-    FecProtection fec_protection,
     QuicAckListenerInterface* listener) {
   if (!fin && iov.total_length == 0) {
     QUIC_BUG << "Attempt to send empty stream frame";
@@ -1204,8 +1163,7 @@ QuicConsumedData QuicConnection::SendStreamData(
   // processing left that may cause received_info_ to change.
   ScopedRetransmissionScheduler alarm_delayer(this);
   ScopedPacketBundler ack_bundler(this, BUNDLE_PENDING_ACK);
-  return packet_generator_.ConsumeData(id, iov, offset, fin, fec_protection,
-                                       listener);
+  return packet_generator_.ConsumeData(id, iov, offset, fin, listener);
 }
 
 void QuicConnection::SendRstStream(QuicStreamId id,
@@ -1519,7 +1477,6 @@ void QuicConnection::WritePendingRetransmissions() {
     }
 
     // Re-packetize the frames with a new packet number for retransmission.
-    // Retransmitted data packets do not use FEC, even when it's enabled.
     // Retransmitted packets use the same packet number length as the
     // original.
     // Flush the packet generator before making a new packet.
@@ -1690,7 +1647,6 @@ bool QuicConnection::WritePacket(SerializedPacket* packet) {
     }
   }
   SetPingAlarm();
-  MaybeSetFecAlarm(packet_number);
   MaybeSetMtuAlarm();
   DVLOG(1) << ENDPOINT << "time we began writing last sent packet: "
            << packet_send_time.ToDebuggingValue();
@@ -1778,10 +1734,6 @@ void QuicConnection::OnSerializedPacket(SerializedPacket* serialized_packet) {
     CloseConnection(QUIC_ENCRYPTION_FAILURE, ConnectionCloseSource::FROM_SELF);
     return;
   }
-  if (serialized_packet->is_fec_packet && fec_alarm_->IsSet()) {
-    // If an FEC packet is serialized with the FEC alarm set, cancel the alarm.
-    fec_alarm_->Cancel();
-  }
   SendOrQueuePacket(serialized_packet);
 }
 
@@ -1792,17 +1744,7 @@ void QuicConnection::OnUnrecoverableError(QuicErrorCode error,
   CloseConnection(error, source);
 }
 
-void QuicConnection::OnResetFecGroup() {
-  if (!fec_alarm_->IsSet()) {
-    return;
-  }
-  // If an FEC Group is closed with the FEC alarm set, cancel the alarm.
-  fec_alarm_->Cancel();
-}
-
 void QuicConnection::OnCongestionWindowChange() {
-  packet_generator_.OnCongestionWindowChange(
-      sent_packet_manager_.EstimateMaxPacketsInFlight(max_packet_length()));
   visitor_->OnCongestionWindowChange(clock_->ApproximateNow());
 }
 
@@ -1813,9 +1755,9 @@ void QuicConnection::OnRttChange() {
     rtt = QuicTime::Delta::FromMicroseconds(
         sent_packet_manager_.GetRttStats()->initial_rtt_us());
   }
+
   if (debug_visitor_)
     debug_visitor_->OnRttChanged(rtt);
-  packet_generator_.OnRttChange(rtt);
 }
 
 void QuicConnection::OnPathDegrading() {
@@ -2115,7 +2057,6 @@ void QuicConnection::CloseConnection(QuicErrorCode error,
   // connection is closed.
   ack_alarm_->Cancel();
   ping_alarm_->Cancel();
-  fec_alarm_->Cancel();
   resume_writes_alarm_->Cancel();
   retransmission_alarm_->Cancel();
   send_alarm_->Cancel();