Move WriteFile and WriteFileDescriptor from file_util to base namespace.

tools/gn/gyp_target_writer.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 "tools/gn/gyp_target_writer.h"
 
 #include <iostream>
 
 #include "base/file_util.h"
 #include "base/files/file_path.h"
@@ skipping 84 matching lines @@
         break;
       }
       default:
         CHECK(0);
     }
   }
 
   file << "  ],\n}\n";
 
   std::string contents = file.str();
-  file_util::WriteFile(gyp_file_path, contents.c_str(),
+  base::WriteFile(gyp_file_path, contents.c_str(),
                        static_cast<int>(contents.size()));
 }
 
 std::ostream& GypTargetWriter::Indent(int spaces) {
   return Indent(out_, spaces);
 }
 
 // static
 std::ostream& GypTargetWriter::Indent(std::ostream& out, int spaces) {
   const char kSpaces[81] =
       "                                        "
       "                                        ";
   CHECK(static_cast<size_t>(spaces) <= arraysize(kSpaces) - 1);
   out.write(kSpaces, spaces);
   return out;
 }