Remove wstring file path helpers from test_file_util.

base/test/test_file_util_win.cc

Index: base/test/test_file_util_win.cc
diff --git a/base/test/test_file_util_win.cc b/base/test/test_file_util_win.cc
index ea0717754f5b22841373fd96961bfc3899c9cd8a..0b7a0c6dfd3e023ee1fb24c49e848743bd5a9688 100644
--- a/base/test/test_file_util_win.cc
+++ b/base/test/test_file_util_win.cc
@@ -267,13 +267,6 @@ using base::DenyFilePermission;
 using base::GetPermissionInfo;
 using base::RestorePermissionInfo;
 
-std::wstring FilePathAsWString(const base::FilePath& path) {
-  return path.value();
-}
-base::FilePath WStringAsFilePath(const std::wstring& path) {
-  return base::FilePath(path);
-}
-
 bool MakeFileUnreadable(const base::FilePath& path) {
   return DenyFilePermission(path, GENERIC_READ);
 }