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

net/tools/quic/test_tools/http_message_test_utils.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_TOOLS_QUIC_TEST_TOOLS_TEST_TOOLS_HTTP_MESSAGE_TEST_UTILS_H_
 #define NET_TOOLS_QUIC_TEST_TOOLS_TEST_TOOLS_HTTP_MESSAGE_TEST_UTILS_H_
 
 #include <string>
 #include <vector>
 
-#include "base/string_piece.h"
+#include "base/strings/string_piece.h"
 #include "net/tools/flip_server/balsa_enums.h"
 #include "net/tools/flip_server/balsa_headers.h"
 
 namespace net {
 namespace tools {
 namespace test {
 
 class HttpConstants {
  public:
   enum Version {
@@ skipping 102 matching lines @@
   void InitializeFields();
 
   DISALLOW_COPY_AND_ASSIGN(HTTPMessage);
 };
 
 }  // namespace test
 }  // namespace tools
 }  // namespace net
 
 #endif  // NET_TOOLS_QUIC_TEST_TOOLS_TEST_TOOLS_HTTP_MESSAGE_TEST_UTILS_H_