Killing off quic V17. Not flag protected.

net/quic/quic_connection.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_connection.h"
 
 #include <string.h>
 #include <sys/types.h>
 #include <algorithm>
 #include <iterator>
@@ skipping 1555 matching lines @@
 void QuicConnection::UpdateStopWaiting(QuicStopWaitingFrame* stop_waiting) {
   stop_waiting->least_unacked = GetLeastUnacked();
   stop_waiting->entropy_hash = sent_entropy_manager_.EntropyHash(
       stop_waiting->least_unacked - 1);
 }
 
 void QuicConnection::SendPing() {
   if (retransmission_alarm_->IsSet()) {
     return;
   }
-  if (version() <= QUIC_VERSION_17) {
-    // TODO(rch): remove this when we remove version 17.
+  if (version() <= QUIC_VERSION_16) {
+    // TODO(rch): remove this when we remove version 15 and 16.
     // This is a horrible hideous hack which we should not support.
     IOVector data;
     char c_data[] = "C";
     data.Append(c_data, 1);
     QuicConsumedData consumed_data =
         packet_generator_.ConsumeData(kCryptoStreamId, data, 0, false,
                                       MAY_FEC_PROTECT, NULL);
     if (consumed_data.bytes_consumed == 0) {
       DLOG(ERROR) << "Unable to send ping!?";
     }
@@ skipping 389 matching lines @@
   // If we changed the generator's batch state, restore original batch state.
   if (!already_in_batch_mode_) {
     DVLOG(1) << "Leaving Batch Mode.";
     connection_->packet_generator_.FinishBatchOperations();
   }
   DCHECK_EQ(already_in_batch_mode_,
             connection_->packet_generator_.InBatchMode());
 }
 
 }  // namespace net