relnote: Protected by --quic_fix_beta_last_max. Fix conservative decrease for n-connection emulatio…

net/quic/core/congestion_control/tcp_cubic_sender_packets.cc

Index: net/quic/core/congestion_control/tcp_cubic_sender_packets.cc
diff --git a/net/quic/core/congestion_control/tcp_cubic_sender_packets.cc b/net/quic/core/congestion_control/tcp_cubic_sender_packets.cc
index ce3518926299c421052090164886540a30683850..8466a244b5cf54e07bad9eacc89ea45c679f325d 100644
--- a/net/quic/core/congestion_control/tcp_cubic_sender_packets.cc
+++ b/net/quic/core/congestion_control/tcp_cubic_sender_packets.cc
@@ -49,6 +49,11 @@ void TcpCubicSenderPackets::SetFromConfig(const QuicConfig& config,
       ContainsQuicTag(config.ReceivedConnectionOptions(), kCCVX)) {
     cubic_.SetFixConvexMode(true);
   }
+  if (FLAGS_quic_fix_beta_last_max &&
+      config.HasReceivedConnectionOptions() &&
+      ContainsQuicTag(config.ReceivedConnectionOptions(), kBLMX)) {
+    cubic_.SetFixBetaLastMax(true);
+  }
 }
 
 void TcpCubicSenderPackets::SetCongestionWindowFromBandwidthAndRtt(