Move directory creation functions to base namespace.

tools/gn/function_write_file.cc

 // Copyright (c) 2013 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 <iostream>
 #include <sstream>
 
 #include "base/file_util.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
@@ skipping 53 matching lines @@
     for (size_t i = 0; i < list.size(); i++)
       contents << list[i].ToString(false) << std::endl;
   } else {
     contents << args[1].ToString(false);
   }
 
   // Write file, creating the directory if necessary.
   base::FilePath file_path =
       scope->settings()->build_settings()->GetFullPath(source_file);
   const std::string& contents_string = contents.str();
-  if (!file_util::CreateDirectory(file_path.DirName())) {
+  if (!base::CreateDirectory(file_path.DirName())) {
     *err = Err(function->function(), "Unable to create directory.",
                "I was using \"" + FilePathToUTF8(file_path.DirName()) + "\".");
     return Value();
   }
   int int_size = static_cast<int>(contents_string.size());
   if (file_util::WriteFile(file_path, contents_string.c_str(), int_size)
       != int_size) {
     *err = Err(function->function(), "Unable to write file.",
                "I was writing \"" + FilePathToUTF8(file_path) + "\".");
     return Value();
   }
   return Value();
 }
 
 }  // namespace functions