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

net/quic/core/congestion_control/tcp_cubic_sender_bytes.cc

Index: net/quic/core/congestion_control/tcp_cubic_sender_bytes.cc
diff --git a/net/quic/core/congestion_control/tcp_cubic_sender_bytes.cc b/net/quic/core/congestion_control/tcp_cubic_sender_bytes.cc
index 2ed7acd26a9f1007c7be6990792fdcb7826d767b..c0cef78466f14d3a847224caac82439e9d3b79c8 100644
--- a/net/quic/core/congestion_control/tcp_cubic_sender_bytes.cc
+++ b/net/quic/core/congestion_control/tcp_cubic_sender_bytes.cc
@@ -57,6 +57,11 @@ void TcpCubicSenderBytes::SetFromConfig(const QuicConfig& config,
       ContainsQuicTag(config.ReceivedConnectionOptions(), kCBQT)) {
     cubic_.SetFixCubicQuantization(true);
   }
+  if (FLAGS_quic_fix_beta_last_max &&
+      config.HasReceivedConnectionOptions() &&
+      ContainsQuicTag(config.ReceivedConnectionOptions(), kBLMX)) {
+    cubic_.SetFixBetaLastMax(true);
+  }
 }
 
 void TcpCubicSenderBytes::SetCongestionWindowFromBandwidthAndRtt(