Remove wstring file path helpers from test_file_util.

base/test/test_file_util_posix.cc

Index: base/test/test_file_util_posix.cc
diff --git a/base/test/test_file_util_posix.cc b/base/test/test_file_util_posix.cc
index ae14bc83951363503f5faccff4606ca837fb9edd..0350ccc0f0e5ee8551e6a5b098de9ac4c53c86a2 100644
--- a/base/test/test_file_util_posix.cc
+++ b/base/test/test_file_util_posix.cc
@@ -17,8 +17,6 @@
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 
-using base::MakeAbsoluteFilePath;
-
 namespace base {
 
 namespace {
@@ -95,13 +93,6 @@ using base::DenyFilePermission;
 using base::GetPermissionInfo;
 using base::RestorePermissionInfo;
 
-std::wstring FilePathAsWString(const base::FilePath& path) {
-  return base::UTF8ToWide(path.value());
-}
-base::FilePath WStringAsFilePath(const std::wstring& path) {
-  return base::FilePath(base::WideToUTF8(path));
-}
-
 bool MakeFileUnreadable(const base::FilePath& path) {
   return DenyFilePermission(path, S_IRUSR | S_IRGRP | S_IROTH);
 }