Refactor preference syncing.

chrome/browser/sync/glue/preference_change_processor.h

-// Copyright (c) 2011 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_SYNC_GLUE_PREFERENCE_CHANGE_PROCESSOR_H_
-#define CHROME_BROWSER_SYNC_GLUE_PREFERENCE_CHANGE_PROCESSOR_H_
-#pragma once
-
-#include <string>
-
-#include "chrome/browser/prefs/pref_change_registrar.h"
-#include "chrome/browser/prefs/pref_service.h"
-#include "chrome/browser/sync/engine/syncapi.h"
-#include "chrome/browser/sync/glue/change_processor.h"
-#include "chrome/browser/sync/glue/sync_backend_host.h"
-#include "content/common/notification_observer.h"
-
-namespace browser_sync {
-
-class PreferenceModelAssociator;
-class UnrecoverableErrorHandler;
-
-// This class is responsible for taking changes from the PrefService and
-// applying them to the sync_api 'syncable' model, and vice versa. All
-// operations and use of this class are from the UI thread.
-class PreferenceChangeProcessor : public ChangeProcessor,
-                                  public NotificationObserver {
- public:
-  PreferenceChangeProcessor(PreferenceModelAssociator* model_associator,
-                            UnrecoverableErrorHandler* error_handler);
-  virtual ~PreferenceChangeProcessor();
-
-  // NotificationObserver implementation.
-  // PrefService -> sync_api model change application.
-  virtual void Observe(NotificationType type,
-                       const NotificationSource& source,
-                       const NotificationDetails& details);
-
-  // sync_api model -> PrefService change application.
-  virtual void ApplyChangesFromSyncModel(
-      const sync_api::BaseTransaction* trans,
-      const sync_api::SyncManager::ChangeRecord* changes,
-      int change_count);
-
- protected:
-  virtual void StartImpl(Profile* profile);
-  virtual void StopImpl();
-
- private:
-  Value* ReadPreference(sync_api::ReadNode* node, std::string* name);
-
-  void StartObserving();
-  void StopObserving();
-
-  // The model we are processing changes from. Non-NULL when |running_| is true.
-  PrefService* pref_service_;
-
-  // The two models should be associated according to this ModelAssociator.
-  PreferenceModelAssociator* model_associator_;
-
-  // Whether we are currently processing a preference change notification.
-  bool processing_pref_change_;
-
-  PrefChangeRegistrar registrar_;
-
-  DISALLOW_COPY_AND_ASSIGN(PreferenceChangeProcessor);
-};
-
-}  // namespace browser_sync
-
-#endif  // CHROME_BROWSER_SYNC_GLUE_PREFERENCE_CHANGE_PROCESSOR_H_