Move kInvalidPacketNumber to QuicDispatcher: the only place it is used. No behavior change.

net/tools/quic/quic_dispatcher.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/tools/quic/quic_dispatcher.h"
 
 #include <utility>
 
 #include "base/debug/stack_trace.h"
 #include "base/logging.h"
@@ skipping 411 matching lines @@
   // set.  Since this may be a client continuing a connection we lost track of
   // via server restart, send a rejection to fast-fail the connection.
   if (!header.public_header.version_flag) {
     DVLOG(1) << "Packet without version arrived for unknown connection ID "
              << header.public_header.connection_id;
     return kFateTimeWait;
   }
 
   // Check that the sequence number is within the range that the client is
   // expected to send before receiving a response from the server.
+  const int kInvalidPacketNumber = 0;
   if (header.packet_number == kInvalidPacketNumber ||
       header.packet_number > kMaxReasonableInitialPacketNumber) {
     return kFateTimeWait;
   }
 
   return kFateProcess;
 }
 
 void QuicDispatcher::CleanUpSession(SessionMap::iterator it,
                                     QuicConnection* connection,
@@ skipping 544 matching lines @@
 void QuicDispatcher::DeliverPacketsToSession(
     const std::list<BufferedPacket>& packets,
     QuicSession* session) {
   for (const BufferedPacket& packet : packets) {
     session->ProcessUdpPacket(packet.server_address, packet.client_address,
                               *(packet.packet));
   }
 }
 
 }  // namespace net