QUIC varz to track measured and predicted bandwidth and rtt histograms

net/quic/congestion_control/tcp_cubic_sender.cc

 // Copyright (c) 2012 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_sender.h"
 
 #include <algorithm>
 
 #include "base/metrics/histogram.h"
 #include "net/quic/congestion_control/rtt_stats.h"
@@ skipping 178 matching lines @@
 QuicByteCount TcpCubicSender::SendWindow() const {
   // What's the current send window in bytes.
   return min(receive_window_, GetCongestionWindow());
 }
 
 QuicBandwidth TcpCubicSender::BandwidthEstimate() const {
   return QuicBandwidth::FromBytesAndTimeDelta(GetCongestionWindow(),
                                               rtt_stats_->SmoothedRtt());
 }
 
+bool TcpCubicSender::HasReliableBandwidthEstimate() const {
+  return !InSlowStart() && !InRecovery();
+}
+
 QuicTime::Delta TcpCubicSender::RetransmissionDelay() const {
   if (!rtt_stats_->HasUpdates()) {
     return QuicTime::Delta::Zero();
   }
   return QuicTime::Delta::FromMicroseconds(
       rtt_stats_->SmoothedRtt().ToMicroseconds() +
       4 * rtt_stats_->mean_deviation().ToMicroseconds());
 }
 
 QuicByteCount TcpCubicSender::GetCongestionWindow() const {
@@ skipping 122 matching lines @@
   // AvailableSendWindow =
   //   CEIL(prr_delivered * ssthresh / BytesInFlightAtLoss) - prr_sent
   if (prr_delivered_ * slowstart_threshold_ * kMaxSegmentSize >
           prr_out_ * bytes_in_flight_before_loss_) {
     return QuicTime::Delta::Zero();
   }
   return QuicTime::Delta::Infinite();
 }
 
 }  // namespace net