Use a direct include of strings headers in net/test/, net/third_party/, net/tools/, net/udp/, net/u…

net/tools/dump_cache/url_to_filename_encoder.cc

 // Copyright (c) 2011 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.
 
 #include <stdlib.h>
 
 #include "base/logging.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
 #include "net/base/net_util.h"
 #include "net/tools/dump_cache/url_to_filename_encoder.h"
 
 using std::string;
 
 namespace {
 
 // Returns 1 if buf is prefixed by "num_digits" of hex digits
 // Teturns 0 otherwise.
 // The function checks for '\0' for string termination.
@@ skipping 264 matching lines @@
       char slash = '/';
 #endif
       output.append(&slash, 1);
       last_slash = index;
     }
   }
   return output;
 }
 
 }  // namespace net