[Sync] Move //sync to //components/sync.

sync/syncable/syncable_read_transaction.cc

-// Copyright 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.
-
-#include "sync/syncable/syncable_read_transaction.h"
-
-namespace syncer {
-namespace syncable {
-
-ReadTransaction::ReadTransaction(const tracked_objects::Location& location,
-                                 Directory* directory)
-    : BaseTransaction(location, "ReadTransaction", INVALID, directory) {
-  Lock();
-}
-
-ReadTransaction::~ReadTransaction() {
-  HandleUnrecoverableErrorIfSet();
-  Unlock();
-}
-
-}  // namespace syncable
-}  // namespace syncer