Killing off quic V17. Not flag protected.

net/quic/quic_framer.cc

Index: net/quic/quic_framer.cc
diff --git a/net/quic/quic_framer.cc b/net/quic/quic_framer.cc
index fd077bc21daf6236e9e249233a89a1501f920056..1a648b85397d9737dddd6f018c66710758ba379f 100644
--- a/net/quic/quic_framer.cc
+++ b/net/quic/quic_framer.cc
@@ -394,7 +394,7 @@ SerializedPacket QuicFramer::BuildDataPacket(
         }
         break;
       case PING_FRAME:
-        if (quic_version_ <= QUIC_VERSION_17) {
+        if (quic_version_ <= QUIC_VERSION_16) {
           LOG(DFATAL) << "Attempt to add a PingFrame in "
                       << QuicVersionToString(quic_version_);
           return kNoPacket;
@@ -1236,7 +1236,7 @@ bool QuicFramer::ProcessFrameData(const QuicPacketHeader& header) {
         continue;
       }
       case PING_FRAME: {
-        if (quic_version_ <= QUIC_VERSION_17) {
+        if (quic_version_ <= QUIC_VERSION_16) {
           LOG(DFATAL) << "Trying to read a Ping in "
                       << QuicVersionToString(quic_version_);
           return RaiseError(QUIC_INTERNAL_ERROR);