sync: Get rid of the now obsolete character_set_converters.h API.

chrome/browser/sync/util/character_set_converters_win.cc

-// Copyright (c) 2009 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 "base/utf_string_conversions.h"
-#include "chrome/browser/sync/util/character_set_converters.h"
-
-namespace browser_sync {
-
-// Returns UTF8 string from the given FilePath.
-std::string FilePathToUTF8(const FilePath& file_path) {
-  return WideToUTF8(file_path.value());
-}
-
-// Returns FilePath from the given UTF8 string.
-FilePath UTF8ToFilePath(const std::string& utf8) {
-  return FilePath(UTF8ToWide(utf8));
-}
-
-}  // namespace browser_sync