Limit QUIC's send algorithm max CWND by the peer's receive buffer and

net/quic/congestion_control/pacing_sender.cc

Index: net/quic/congestion_control/pacing_sender.cc
diff --git a/net/quic/congestion_control/pacing_sender.cc b/net/quic/congestion_control/pacing_sender.cc
index addf426b5fe10a91194f8f162ea2cbbf47ffd860..123f84ab3d81fc0ac05b51396862c3ccdb28b23e 100644
--- a/net/quic/congestion_control/pacing_sender.cc
+++ b/net/quic/congestion_control/pacing_sender.cc
@@ -36,6 +36,10 @@ void PacingSender::SetNumEmulatedConnections(int num_connections) {
   sender_->SetNumEmulatedConnections(num_connections);
 }
 
+void PacingSender::SetMaxCongestionWindow(QuicByteCount max_congestion_window) {
+  sender_->SetMaxCongestionWindow(max_congestion_window);
+}
+
 void PacingSender::OnCongestionEvent(bool rtt_updated,
                                      QuicByteCount bytes_in_flight,
                                      const CongestionVector& acked_packets,