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

net/quic/core/quic_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_QUIC_PROTOCOL_H_
 #define NET_QUIC_QUIC_PROTOCOL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 82 matching lines @@
   bool multipath_flag;
   bool reset_flag;
   bool version_flag;
   QuicPacketNumberLength packet_number_length;
   QuicVersionVector versions;
   // nonce contains an optional, 32-byte nonce value. If not included in the
   // packet, |nonce| will be empty.
   DiversificationNonce* nonce;
 };
 
-// An integer which cannot be a packet number.
-const QuicPacketNumber kInvalidPacketNumber = 0;
-
 // Header for Data packets.
 struct NET_EXPORT_PRIVATE QuicPacketHeader {
   QuicPacketHeader();
   explicit QuicPacketHeader(const QuicPacketPublicHeader& header);
   QuicPacketHeader(const QuicPacketHeader& other);
 
   NET_EXPORT_PRIVATE friend std::ostream& operator<<(std::ostream& os,
                                                      const QuicPacketHeader& s);
 
   QuicPacketPublicHeader public_header;
@@ skipping 685 matching lines @@
       : iov(iov), iov_count(iov_count), total_length(total_length) {}
 
   const struct iovec* iov;
   const int iov_count;
   const size_t total_length;
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_PROTOCOL_H_