Remove unused windowed RTT logic from RttStats

net/quic/core/congestion_control/rtt_stats.cc

Index: net/quic/core/congestion_control/rtt_stats.cc
diff --git a/net/quic/core/congestion_control/rtt_stats.cc b/net/quic/core/congestion_control/rtt_stats.cc
index 91d3e2ad3c089f0b66e51f6107f1c733922ee654..086511cd3a2fc45dab13efa69c5fb8120dce1d83 100644
--- a/net/quic/core/congestion_control/rtt_stats.cc
+++ b/net/quic/core/congestion_control/rtt_stats.cc
@@ -20,8 +20,6 @@ const float kAlpha = 0.125f;
 const float kOneMinusAlpha = (1 - kAlpha);
 const float kBeta = 0.25f;
 const float kOneMinusBeta = (1 - kBeta);
-// 10-second window length for windowed min RTT.
-const int kMinRttWindowLengthMs = 10000;
 
 }  // namespace
 
@@ -31,20 +29,7 @@ RttStats::RttStats()
       smoothed_rtt_(QuicTime::Delta::Zero()),
       previous_srtt_(QuicTime::Delta::Zero()),
       mean_deviation_(QuicTime::Delta::Zero()),
-      initial_rtt_us_(kInitialRttMs * kNumMicrosPerMilli),
-      forced_windowed_min_rtt_(QuicTime::Delta::Zero()),
-      forced_windowed_min_rtt_time_(QuicTime::Zero()),
-      num_samples_for_forced_min_(0),
-      windowed_min_rtt_(
-          QuicTime::Delta::FromMilliseconds(kMinRttWindowLengthMs),
-          QuicTime::Delta::Zero(),
-          QuicTime::Zero()) {}
-
-void RttStats::SampleNewWindowedMinRtt(uint32_t num_samples) {
-  num_samples_for_forced_min_ = num_samples;
-  forced_windowed_min_rtt_ = QuicTime::Delta::Zero();
-  forced_windowed_min_rtt_time_ = QuicTime::Zero();
-}
+      initial_rtt_us_(kInitialRttMs * kNumMicrosPerMilli) {}
 
 void RttStats::ExpireSmoothedMetrics() {
   mean_deviation_ = max(mean_deviation_,
@@ -71,7 +56,6 @@ void RttStats::UpdateRtt(QuicTime::Delta send_delta,
   if (min_rtt_.IsZero() || min_rtt_ > send_delta) {
     min_rtt_ = send_delta;
   }
-  UpdateWindowedMinRtt(send_delta, now);
 
   // Correct for ack_delay if information received from the peer results in a
   // positive RTT sample. Otherwise, we use the send_delta as a reasonable
@@ -98,33 +82,12 @@ void RttStats::UpdateRtt(QuicTime::Delta send_delta,
   }
 }
 
-void RttStats::UpdateWindowedMinRtt(QuicTime::Delta rtt_sample, QuicTime now) {
-  // Update windowed_min_rtt.
-  windowed_min_rtt_.Update(rtt_sample, now);
-  if (num_samples_for_forced_min_ <= 0) {
-    return;
-  }
-  // Reset windowed_min_rtt to the min of num_samples_for_forced_min_ samples.
-  if (forced_windowed_min_rtt_.IsZero() ||
-      rtt_sample <= forced_windowed_min_rtt_) {
-    forced_windowed_min_rtt_ = rtt_sample;
-    forced_windowed_min_rtt_time_ = now;
-  }
-  if (num_samples_for_forced_min_ == 1) {
-    windowed_min_rtt_.Reset(forced_windowed_min_rtt_,
-                            forced_windowed_min_rtt_time_);
-  }
-  --num_samples_for_forced_min_;
-}
-
 void RttStats::OnConnectionMigration() {
   latest_rtt_ = QuicTime::Delta::Zero();
   min_rtt_ = QuicTime::Delta::Zero();
   smoothed_rtt_ = QuicTime::Delta::Zero();
   mean_deviation_ = QuicTime::Delta::Zero();
   initial_rtt_us_ = kInitialRttMs * kNumMicrosPerMilli;
-  num_samples_for_forced_min_ = 0;
-  windowed_min_rtt_.Reset(QuicTime::Delta::Zero(), QuicTime::Zero());
 }
 
 }  // namespace net