Add QuicStringPiece which is actually StringPiece.

net/quic/core/frames/quic_ack_frame.h

 // Copyright (c) 2016 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_CORE_FRAMES_QUIC_ACK_FRAME_H_
 #define NET_QUIC_CORE_FRAMES_QUIC_ACK_FRAME_H_
 
 #include <ostream>
 #include <string>
 
-#include "base/strings/string_piece.h"
 #include "net/quic/core/quic_types.h"
 #include "net/quic/platform/api/quic_containers.h"
 #include "net/quic/platform/api/quic_export.h"
 
 namespace net {
 
 // A sequence of packet numbers where each number is unique. Intended to be used
 // in a sliding window fashion, where smaller old packet numbers are removed and
 // larger new packet numbers are added, with the occasional random access.
 class QUIC_EXPORT_PRIVATE PacketNumberQueue {
@@ skipping 102 matching lines @@
 // as missing.
 // Always returns false for packet numbers less than least_unacked.
 QUIC_EXPORT_PRIVATE bool IsAwaitingPacket(
     const QuicAckFrame& ack_frame,
     QuicPacketNumber packet_number,
     QuicPacketNumber peer_least_packet_awaiting_ack);
 
 }  // namespace net
 
 #endif  // NET_QUIC_CORE_FRAMES_QUIC_ACK_FRAME_H_