Remove FixRate congestion frame type.

net/quic/quic_protocol.h

Index: net/quic/quic_protocol.h
diff --git a/net/quic/quic_protocol.h b/net/quic/quic_protocol.h
index b57619dab2b33c830bcf68338c43ac36b47717cb..170a40ce9a651be59f9902bc54c6763611e1137d 100644
--- a/net/quic/quic_protocol.h
+++ b/net/quic/quic_protocol.h
@@ -712,7 +712,6 @@ struct NET_EXPORT_PRIVATE QuicAckFrame {
 enum CongestionFeedbackType {
   kTCP,  // Used to mimic TCP.
   kInterArrival,  // Use additional inter arrival information.
-  kFixRate,  // Provided for testing.
 };
 
 // Defines for all types of congestion control algorithms that can be used in
@@ -722,7 +721,6 @@ enum CongestionFeedbackType {
 enum CongestionControlType {
   kCubic,
   kReno,
-  kFixRateCongestionControl,  // Provided for testing.
   kBBR,
 };
 
@@ -746,11 +744,6 @@ struct NET_EXPORT_PRIVATE CongestionFeedbackMessageInterArrival {
   TimeMap received_packet_times;
 };
 
-struct NET_EXPORT_PRIVATE CongestionFeedbackMessageFixRate {
-  CongestionFeedbackMessageFixRate();
-  QuicBandwidth bitrate;
-};
-
 struct NET_EXPORT_PRIVATE QuicCongestionFeedbackFrame {
   QuicCongestionFeedbackFrame();
   ~QuicCongestionFeedbackFrame();
@@ -763,7 +756,6 @@ struct NET_EXPORT_PRIVATE QuicCongestionFeedbackFrame {
   // is non-trivial, C++ prohibits it.
   CongestionFeedbackMessageTCP tcp;
   CongestionFeedbackMessageInterArrival inter_arrival;
-  CongestionFeedbackMessageFixRate fix_rate;
 };
 
 struct NET_EXPORT_PRIVATE QuicRstStreamFrame {