net: Update the include paths of base/string_piece.h to its new location.

net/tools/flip_server/balsa_headers.h

 // Copyright (c) 2009 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_TOOLS_FLIP_SERVER_BALSA_HEADERS_H_
 #define NET_TOOLS_FLIP_SERVER_BALSA_HEADERS_H_
 
 #include <algorithm>
 #include <iosfwd>
 #include <iterator>
 #include <string>
 #include <utility>
 #include <vector>
 
+#include "base/logging.h"
 #include "base/port.h"
-#include "base/logging.h"
-#include "base/string_piece.h"
+#include "base/strings/string_piece.h"
 #include "net/tools/flip_server/balsa_enums.h"
 #include "net/tools/flip_server/string_piece_utils.h"
 
 namespace net {
 
 // WARNING:
 // Note that -no- char* returned by any function in this
 // file is null-terminated.
 
 // This class exists to service the specific needs of BalsaHeaders.
@@ skipping 1100 matching lines @@
   size_t end_of_firstline_idx_;
 
   bool transfer_encoding_is_chunked_;
 
   HeaderLines header_lines_;
 };
 
 }  // namespace net
 
 #endif  // NET_TOOLS_FLIP_SERVER_BALSA_HEADERS_H_