Add QuicStringPiece which is actually StringPiece.

net/tools/quic/quic_simple_client.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.
 //
 // A toy client, which connects to a specified port and sends QUIC
 // request to that endpoint.
 
 #ifndef NET_TOOLS_QUIC_QUIC_SIMPLE_CLIENT_H_
 #define NET_TOOLS_QUIC_QUIC_SIMPLE_CLIENT_H_
 
 #include <stddef.h>
 
 #include <memory>
 #include <string>
 
 #include "base/command_line.h"
 #include "base/macros.h"
-#include "base/strings/string_piece.h"
 #include "net/base/ip_address.h"
 #include "net/base/ip_endpoint.h"
 #include "net/http/http_response_headers.h"
 #include "net/log/net_log.h"
 #include "net/quic/chromium/quic_chromium_packet_reader.h"
 #include "net/quic/core/quic_config.h"
 #include "net/quic/core/quic_spdy_stream.h"
 #include "net/quic/platform/impl/quic_chromium_clock.h"
 #include "net/tools/quic/quic_client_base.h"
 
@@ skipping 68 matching lines @@
   bool packet_reader_started_;
 
   base::WeakPtrFactory<QuicSimpleClient> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicSimpleClient);
 };
 
 }  // namespace net
 
 #endif  // NET_TOOLS_QUIC_QUIC_SIMPLE_CLIENT_H_