Allow QUIC's BBR congestion control to be negotiated in the crypto

net/quic/quic_sent_packet_manager.cc

 // Copyright 2013 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/quic_sent_packet_manager.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/stl_util.h"
@@ skipping 64 matching lines @@
 
 QuicSentPacketManager::~QuicSentPacketManager() {
 }
 
 void QuicSentPacketManager::SetFromConfig(const QuicConfig& config) {
   if (config.HasReceivedInitialRoundTripTimeUs() &&
       config.ReceivedInitialRoundTripTimeUs() > 0) {
     rtt_stats_.set_initial_rtt_us(min(kMaxInitialRoundTripTimeUs,
                                       config.ReceivedInitialRoundTripTimeUs()));
   }
-  if (config.congestion_control() == kPACE) {
+  // TODO(ianswett): BBR is currently a server only feature.
+  if (config.HasReceivedCongestionOptions() &&
+      ContainsQuicTag(config.ReceivedCongestionOptions(), kTBBR)) {
+    send_algorithm_.reset(
+        SendAlgorithmInterface::Create(clock_, &rtt_stats_, kTCPBBR, stats_));
+  }
+  if (config.congestion_feedback() == kPACE) {
     MaybeEnablePacing();
   }
   if (config.HasReceivedLossDetection() &&
       config.ReceivedLossDetection() == kTIME) {
     loss_algorithm_.reset(LossDetectionInterface::Create(kTime));
   }
   send_algorithm_->SetFromConfig(config, is_server_);
 }
 
 // TODO(ianswett): Combine this method with OnPacketSent once packets are always
@@ skipping 635 matching lines @@
     return;
   }
 
   using_pacing_ = true;
   send_algorithm_.reset(
       new PacingSender(send_algorithm_.release(),
                        QuicTime::Delta::FromMicroseconds(1)));
 }
 
 }  // namespace net