gfe-relnote: (n/a) In QUIC BBR and BBRv2, add a flag for MaxAckHeightTracker to determine when to start a new ack aggregation epoch. No behavior change.

PiperOrigin-RevId: 275301395
Change-Id: I3aae83b36ee654ac764ce8b672ad1b3884ec8165

quic/core/congestion_control/bandwidth_sampler.cc

diff --git a/quic/core/congestion_control/bandwidth_sampler.cc b/quic/core/congestion_control/bandwidth_sampler.cc
index 85de251..2555e0f 100644
--- a/quic/core/congestion_control/bandwidth_sampler.cc
+++ b/quic/core/congestion_control/bandwidth_sampler.cc
@@ -30,7 +30,9 @@
       bandwidth_estimate * (ack_time - aggregation_epoch_start_time_);
   // Reset the current aggregation epoch as soon as the ack arrival rate is less
   // than or equal to the max bandwidth.
-  if (aggregation_epoch_bytes_ <= expected_bytes_acked) {
+  if (aggregation_epoch_bytes_ <=
+      GetQuicFlag(FLAGS_quic_ack_aggregation_bandwidth_threshold) *
+          expected_bytes_acked) {
     // Reset to start measuring a new aggregation epoch.
     aggregation_epoch_bytes_ = bytes_acked;
     aggregation_epoch_start_time_ = ack_time;