Stub for BBRv2, based on TCP congestion feedback frames.

net/quic/congestion_control/receive_algorithm_interface.cc

Index: net/quic/congestion_control/receive_algorithm_interface.cc
diff --git a/net/quic/congestion_control/receive_algorithm_interface.cc b/net/quic/congestion_control/receive_algorithm_interface.cc
index f5672f804156fe3c61fef3b9ba77a1934529e24c..5384bdcddf76fb9716d480d8bb50d2329d602f83 100644
--- a/net/quic/congestion_control/receive_algorithm_interface.cc
+++ b/net/quic/congestion_control/receive_algorithm_interface.cc
@@ -15,6 +15,9 @@ ReceiveAlgorithmInterface* ReceiveAlgorithmInterface::Create(
   switch (type) {
     case kTCP:
       return new TcpReceiver();
+    case kTCPBBR:
+      LOG(DFATAL) << "TCPBBR is not yet supported.";
+      return NULL;
     case kInterArrival:
       LOG(DFATAL) << "InterArrivalSendAlgorithm no longer supported.";
       return NULL;