Move AppendFile and *CurrentDirectory to the base namespace.

tools/gn/filesystem_utils.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/filesystem_utils.h"
 
 #include <algorithm>
 
 #include "base/file_util.h"
 #include "base/logging.h"
@@ skipping 648 matching lines @@
 
   for (size_t i = initial_path_comp_to_use; i < path_comp.size(); i++) {
     result_str.append(FilePathToUTF8(path_comp[i]));
     result_str.push_back('/');
   }
   return SourceDir(result_str);
 }
 
 SourceDir SourceDirForCurrentDirectory(const base::FilePath& source_root) {
   base::FilePath cd;
-  file_util::GetCurrentDirectory(&cd);
+  base::GetCurrentDirectory(&cd);
   return SourceDirForPath(source_root, cd);
 }
 
 SourceDir GetToolchainOutputDir(const Settings* settings) {
   const OutputFile& toolchain_subdir = settings->toolchain_output_subdir();
 
   std::string result = settings->build_settings()->build_dir().value();
   if (!toolchain_subdir.value().empty())
     result.append(toolchain_subdir.value());
 
@@ skipping 50 matching lines @@
   return GetGenDirForSourceDir(target->settings(), target->label().dir());
 }
 
 SourceDir GetCurrentOutputDir(const Scope* scope) {
   return GetOutputDirForSourceDir(scope->settings(), scope->GetSourceDir());
 }
 
 SourceDir GetCurrentGenDir(const Scope* scope) {
   return GetGenDirForSourceDir(scope->settings(), scope->GetSourceDir());
 }