Adds QUIC_VERSION_24 which uses SPDY/4 header compression instead of SPDY/3.

net/quic/quic_protocol.cc

 // 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.
 
 #include "net/quic/quic_protocol.h"
 
 #include "base/stl_util.h"
 #include "net/quic/quic_utils.h"
 
 using base::StringPiece;
@@ skipping 144 matching lines @@
   }
   return supported_versions;
 }
 
 QuicTag QuicVersionToQuicTag(const QuicVersion version) {
   switch (version) {
     case QUIC_VERSION_22:
       return MakeQuicTag('Q', '0', '2', '2');
     case QUIC_VERSION_23:
       return MakeQuicTag('Q', '0', '2', '3');
+    case QUIC_VERSION_24:
+      return MakeQuicTag('Q', '0', '2', '4');
     default:
       // This shold be an ERROR because we should never attempt to convert an
       // invalid QuicVersion to be written to the wire.
       LOG(ERROR) << "Unsupported QuicVersion: " << version;
       return 0;
   }
 }
 
 QuicVersion QuicTagToQuicVersion(const QuicTag version_tag) {
   for (size_t i = 0; i < arraysize(kSupportedQuicVersions); ++i) {
     if (version_tag == QuicVersionToQuicTag(kSupportedQuicVersions[i])) {
       return kSupportedQuicVersions[i];
     }
   }
   // Reading from the client so this should not be considered an ERROR.
   DVLOG(1) << "Unsupported QuicTag version: "
            << QuicUtils::TagToString(version_tag);
   return QUIC_VERSION_UNSUPPORTED;
 }
 
 #define RETURN_STRING_LITERAL(x) \
 case x: \
 return #x
 
 string QuicVersionToString(const QuicVersion version) {
   switch (version) {
     RETURN_STRING_LITERAL(QUIC_VERSION_22);
     RETURN_STRING_LITERAL(QUIC_VERSION_23);
+    RETURN_STRING_LITERAL(QUIC_VERSION_24);
     default:
       return "QUIC_VERSION_UNSUPPORTED";
   }
 }
 
 string QuicVersionVectorToString(const QuicVersionVector& versions) {
   string result = "";
   for (size_t i = 0; i < versions.size(); ++i) {
     if (i != 0) {
       result.append(",");
@@ skipping 508 matching lines @@
       sent_time(sent_time),
       bytes_sent(0),
       nack_count(0),
       transmission_type(transmission_type),
       all_transmissions(nullptr),
       in_flight(false),
       is_unackable(false),
       is_fec_packet(false) {}
 
 }  // namespace net