Use chromium logic for database identifier<->origin conversions

webkit/base/origin_url_conversions.h

-// Copyright 2013 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_ORIGIN_URL_CONVERSIONS_H_
-#define WEBKIT_BASE_ORIGIN_URL_CONVERSIONS_H_
-
-#include <string>
-#include "webkit/base/webkit_base_export.h"
-
-class GURL;
-
-namespace webkit_base {
-
-// Returns the origin url for the given |identifier| and vice versa.
-// The origin identifier string is a serialized form of a security origin
-// and can be used as a path name as it contains no "/" or other possibly
-// unsafe characters. (See WebKit's SecurityOrigin code for more details.)
-//
-// Example:
-//   "http://www.example.com:80/"'s identifier should look like:
-//   "http_www.example.host_80"
-WEBKIT_BASE_EXPORT GURL GetOriginURLFromIdentifier(
-    const std::string& identifier);
-
-WEBKIT_BASE_EXPORT std::string GetOriginIdentifierFromURL(const GURL& url);
-
-}  // namespace webkit_base
-
-#endif  // WEBKIT_BASE_ORIGIN_URL_CONVERSIONS_H_