Implement a QUIC No PRR connection option, NPRR. Protected by FLAGS_quic_allow_no_prr

net/quic/crypto/crypto_protocol.h

 // Copyright (c) 2012 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.
 
 #ifndef NET_QUIC_CRYPTO_CRYPTO_PROTOCOL_H_
 #define NET_QUIC_CRYPTO_CRYPTO_PROTOCOL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 80 matching lines @@
 const QuicTag kTLPR = TAG('T', 'L', 'P', 'R');   // Tail loss probe delay of
                                                  // 0.5RTT.
 const QuicTag kACKD = TAG('A', 'C', 'K', 'D');   // Ack decimation style acking.
 const QuicTag kAKD2 = TAG('A', 'K', 'D', '2');   // Ack decimation tolerating
                                                  // out of order packets.
 const QuicTag kAKD3 = TAG('A', 'K', 'D', '3');   // Ack decimation style acking
                                                  // with 1/8 RTT acks.
 const QuicTag kAKD4 = TAG('A', 'K', 'D', '4');   // Ack decimation with 1/8 RTT
                                                  // tolerating out of order.
 const QuicTag kSSLR = TAG('S', 'S', 'L', 'R');   // Slow Start Large Reduction.
+const QuicTag kNPRR = TAG('N', 'P', 'R', 'R');   // Pace at unity instead of PRR
 const QuicTag k5RTO = TAG('5', 'R', 'T', 'O');   // Close connection on 5 RTOs
 const QuicTag kCTIM = TAG('C', 'T', 'I', 'M');   // Client timestamp in seconds
                                                  // since UNIX epoch.
 const QuicTag kDHDT = TAG('D', 'H', 'D', 'T');   // Disable HPACK dynamic table.
 const QuicTag kIPFS = TAG('I', 'P', 'F', 'S');   // Immediate Forward Secrecy.
 
 // Optional support of truncated Connection IDs.  If sent by a peer, the value
 // is the minimum number of bytes allowed for the connection ID sent to the
 // peer.
 const QuicTag kTCID = TAG('T', 'C', 'I', 'D');   // Connection ID truncation.
@@ skipping 125 matching lines @@
 // amplification factor of any mirror DoS attack.
 //
 // A client may pad an inchoate client hello to a size larger than
 // kClientHelloMinimumSize to make it more likely to receive a complete
 // rejection message.
 const size_t kClientHelloMinimumSize = 1024;
 
 }  // namespace net
 
 #endif  // NET_QUIC_CRYPTO_CRYPTO_PROTOCOL_H_