sync: Finish non-blocking type encryption support

sync/engine/directory_cryptographer_provider.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 "sync/engine/directory_cryptographer_provider.h"
-
-#include "sync/syncable/directory.h"
-#include "sync/syncable/syncable_read_transaction.h"
-
-namespace syncer {
-
-DirectoryCryptographerProvider::DirectoryCryptographerProvider(
-    syncable::Directory* dir)
-    : dir_(dir) {
-}
-
-DirectoryCryptographerProvider::~DirectoryCryptographerProvider() {
-}
-
-bool DirectoryCryptographerProvider::InitScopedCryptographerRef(
-    ScopedCryptographerRef* scoped) {
-  scoped->Initialize(new ScopedDirectoryCryptographerInternal(dir_));
-  return scoped->IsValid();
-}
-
-ScopedDirectoryCryptographerInternal::ScopedDirectoryCryptographerInternal(
-    syncable::Directory* dir)
-    : dir_(dir), trans_(FROM_HERE, dir) {
-}
-
-ScopedDirectoryCryptographerInternal::~ScopedDirectoryCryptographerInternal() {
-}
-
-Cryptographer* ScopedDirectoryCryptographerInternal::Get() const {
-  return dir_->GetCryptographer(&trans_);
-}
-
-}  // namespace syncer