[Sync] Move some things from driver to base.

components/sync/driver/system_encryptor.cc

-// Copyright 2014 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 "components/sync/driver/system_encryptor.h"
-
-#include "components/os_crypt/os_crypt.h"
-
-namespace syncer {
-
-SystemEncryptor::~SystemEncryptor() {}
-
-bool SystemEncryptor::EncryptString(const std::string& plaintext,
-                                    std::string* ciphertext) {
-  return ::OSCrypt::EncryptString(plaintext, ciphertext);
-}
-
-bool SystemEncryptor::DecryptString(const std::string& ciphertext,
-                                    std::string* plaintext) {
-  return ::OSCrypt::DecryptString(ciphertext, plaintext);
-}
-
-}  // namespace syncer