Add a data structure QuicMultipathTransmissionsMap which is not in use now.

net/quic/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>
 #include <limits>
@@ skipping 23 matching lines @@
 
 namespace net {
 
 class QuicPacket;
 struct QuicPacketHeader;
 
 typedef uint64 QuicConnectionId;
 typedef uint32 QuicStreamId;
 typedef uint64 QuicStreamOffset;
 typedef uint64 QuicPacketNumber;
+typedef uint8 QuicPathId;
 typedef QuicPacketNumber QuicFecGroupNumber;
 typedef uint64 QuicPublicResetNonceProof;
 typedef uint8 QuicPacketEntropyHash;
 typedef uint32 QuicHeaderId;
 // QuicTag is the type of a tag in the wire protocol.
 typedef uint32 QuicTag;
 typedef std::vector<QuicTag> QuicTagVector;
 typedef std::map<QuicTag, std::string> QuicTagValueMap;
 // TODO(rtenneti): Didn't use SpdyPriority because SpdyPriority is uint8 and
 // QuicPriority is uint32. Use SpdyPriority when we change the QUIC_VERSION.
@@ skipping 1184 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_