Delete unused files.

webkit/base/file_path_string_conversions.h

-// Copyright (c) 2012 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.
-
-#ifndef WEBKIT_BASE_FILE_PATH_STRING_CONVERSIONS_H_
-#define WEBKIT_BASE_FILE_PATH_STRING_CONVERSIONS_H_
-
-#include "base/files/file_path.h"
-#include "webkit/base/webkit_base_export.h"
-
-namespace WebKit {
-class WebString;
-}
-
-namespace webkit_base {
-
-// DEPRECATED
-// Use FilePath::{As,From}UTF16Unsafe instead.
-
-WEBKIT_BASE_EXPORT base::FilePath::StringType WebStringToFilePathString(
-    const WebKit::WebString& str);
-WEBKIT_BASE_EXPORT WebKit::WebString FilePathStringToWebString(
-    const base::FilePath::StringType& str);
-WEBKIT_BASE_EXPORT base::FilePath WebStringToFilePath(
-    const WebKit::WebString& str);
-WEBKIT_BASE_EXPORT WebKit::WebString FilePathToWebString(
-    const base::FilePath& file_path);
-
-}  // namespace webkit_base
-
-#endif  // WEBKIT_BASE_FILE_PATH_STRING_CONVERSIONS_H_