Use BBR for Quartc congestion control.

net/quic/quartc/quartc_factory.cc

 // Copyright (c) 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/quartc/quartc_factory.h"
 
 #include "net/quic/core/crypto/quic_random.h"
 #include "net/quic/platform/api/quic_socket_address.h"
 #include "net/quic/quartc/quartc_session.h"
 
@@ skipping 94 matching lines @@
 
 std::unique_ptr<QuartcSessionInterface> QuartcFactory::CreateQuartcSession(
     const QuartcSessionConfig& quartc_session_config) {
   DCHECK(quartc_session_config.packet_transport);
 
   Perspective perspective = quartc_session_config.is_server
                                 ? Perspective::IS_SERVER
                                 : Perspective::IS_CLIENT;
   std::unique_ptr<QuicConnection> quic_connection =
       CreateQuicConnection(quartc_session_config, perspective);
+  QuicTagVector copt;
+  if (quartc_session_config.congestion_control ==
+      QuartcCongestionControl::kBBR) {
+    copt.push_back(kTBBR);
+  }
   QuicConfig quic_config;
+  quic_config.SetConnectionOptionsToSend(copt);
+  quic_config.SetClientConnectionOptions(copt);
   return std::unique_ptr<QuartcSessionInterface>(new QuartcSession(
       std::move(quic_connection), quic_config,
       quartc_session_config.unique_remote_server_id, perspective,
       this /*QuicConnectionHelperInterface*/, clock_.get()));
 }
 
 std::unique_ptr<QuicConnection> QuartcFactory::CreateQuicConnection(
     const QuartcSessionConfig& quartc_session_config,
     Perspective perspective) {
   // The QuicConnection will take the ownership.
@@ skipping 34 matching lines @@
   return &buffer_allocator_;
 }
 
 std::unique_ptr<QuartcFactoryInterface> CreateQuartcFactory(
     const QuartcFactoryConfig& factory_config) {
   return std::unique_ptr<QuartcFactoryInterface>(
       new QuartcFactory(factory_config));
 }
 
 }  // namespace net