Convert BlockFiles to use FilePath instead of wstring.

net/disk_cache/cache_util_posix.cc

 // Copyright (c) 2006-2008 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 "net/disk_cache/cache_util.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/string_util.h"
 
@@ skipping 20 matching lines @@
 }
 
 bool DeleteCacheFile(const FilePath& name) {
   return file_util::Delete(name, false);
 }
 
 void DeleteCache(const std::wstring& path, bool remove_folder) {
   DeleteCache(FilePath::FromWStringHack(path), remove_folder);
 }
 
-bool DeleteCacheFile(const std::wstring& name) {
-  return DeleteCacheFile(FilePath::FromWStringHack(name));
-}
-
 }  // namespace disk_cache