Move QuicIoVector into its own header file. 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 746 matching lines @@
   QuicPacketNumber packet_number;
   const QuicFrames& retransmittable_frames;
   TransmissionType transmission_type;
   QuicPathId path_id;
   bool has_crypto_handshake;
   int num_padding_bytes;
   EncryptionLevel encryption_level;
   QuicPacketNumberLength packet_number_length;
 };
 
-// Convenience wrapper to wrap an iovec array and the total length, which must
-// be less than or equal to the actual total length of the iovecs.
-struct NET_EXPORT_PRIVATE QuicIOVector {
-  QuicIOVector(const struct iovec* iov, int iov_count, size_t total_length)
-      : 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_