[fsp] Separate logic for saving/restoring state to a separate class.

chrome/browser/chromeos/file_system_provider/registry_interface.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 "chrome/browser/chromeos/file_system_provider/observed_entry.h"
+#include "chrome/browser/chromeos/file_system_provider/registry_interface.h"
 
 namespace chromeos {
 namespace file_system_provider {
 
-ObservedEntry::ObservedEntry() : recursive(false) {
+RegistryInterface::~RegistryInterface() {
 }
 
-ObservedEntry::~ObservedEntry() {
+RegistryInterface::RestoredFileSystem::RestoredFileSystem() {
+}
+
+RegistryInterface::RestoredFileSystem::~RestoredFileSystem() {
 }
 
 }  // namespace file_system_provider
 }  // namespace chromeos