Implement LoginDatabase on all platforms.

chrome/browser/password_manager/login_database_mac.h

-// 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.
-
-#ifndef CHROME_BROWSER_PASSWORD_MANAGER_LOGIN_DATABASE_MAC_H_
-#define CHROME_BROWSER_PASSWORD_MANAGER_LOGIN_DATABASE_MAC_H_
-
-#include "chrome/browser/password_manager/login_database.h"
-
-#include <string>
-
-// A trivial subclass of LoginDatabase that nulls out passwords, so that we can
-// use the rest of the database as a suplemental storage system to complement
-// Keychain, providing storage of fields Keychain doesn't allow for.
-class LoginDatabaseMac : public LoginDatabase {
- public:
-  LoginDatabaseMac() {}
-  virtual ~LoginDatabaseMac() {}
-
- protected:
-  // Stub implementations that always return an empty string.
-  virtual std::string EncryptedString(const string16& plain_text) const;
-  virtual string16 DecryptedString(const std::string& cipher_text) const;
-};
-
-
-#endif  // CHROME_BROWSER_PASSWORD_MANAGER_LOGIN_DATABASE_MAC_H_