Create a new QUIC BBR ack aggregation patch which allows extra CWND only when bytes in flight has g…

net/quic/core/congestion_control/bbr_sender.h

Index: net/quic/core/congestion_control/bbr_sender.h
diff --git a/net/quic/core/congestion_control/bbr_sender.h b/net/quic/core/congestion_control/bbr_sender.h
index 8b736867d264caa8d03abdf88a129d64a01d6f73..767f061476ecbd5ebfde42e97154883435b9365a 100644
--- a/net/quic/core/congestion_control/bbr_sender.h
+++ b/net/quic/core/congestion_control/bbr_sender.h
@@ -249,6 +249,10 @@ class QUIC_EXPORT_PRIVATE BbrSender : public SendAlgorithmInterface {
   QuicTime aggregation_epoch_start_time_;
   QuicByteCount aggregation_epoch_bytes_;
 
+  // The number of bytes acknowledged since the last time bytes in flight
+  // dropped below the target window.
+  QuicByteCount bytes_acked_since_queue_drained_;
+
   // Minimum RTT estimate.  Automatically expires within 10 seconds (and
   // triggers PROBE_RTT mode) if no new value is sampled during that period.
   QuicTime::Delta min_rtt_;