[Sync] Split DirectoryChangeListener for thread-safety

chrome/browser/sync/js_directory_change_listener.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_JS_DIRECTORY_CHANGE_LISTENER_H_
-#define CHROME_BROWSER_SYNC_JS_DIRECTORY_CHANGE_LISTENER_H_
-#pragma once
-
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "chrome/browser/sync/syncable/directory_change_listener.h"
-
-namespace browser_sync {
-
-class JsEventRouter;
-
-// Routes SyncManager events to a JsEventRouter.
-class JsDirectoryChangeListener : public syncable::DirectoryChangeListener {
- public:
-  // |parent_router| must be non-NULL and must outlive this object.
-  explicit JsDirectoryChangeListener(JsEventRouter* parent_router);
-
-  virtual ~JsDirectoryChangeListener();
-
-  // syncable::DirectoryChangeListener implementation.
-  virtual void HandleCalculateChangesChangeEventFromSyncApi(
-      const syncable::OriginalEntries& originals,
-      const syncable::WriterTag& writer,
-      syncable::BaseTransaction* trans) OVERRIDE;
-  virtual void HandleCalculateChangesChangeEventFromSyncer(
-      const syncable::OriginalEntries& originals,
-      const syncable::WriterTag& writer,
-      syncable::BaseTransaction* trans) OVERRIDE;
-  virtual syncable::ModelTypeBitSet HandleTransactionEndingChangeEvent(
-      syncable::BaseTransaction* trans) OVERRIDE;
-  virtual void HandleTransactionCompleteChangeEvent(
-      const syncable::ModelTypeBitSet& models_with_changes) OVERRIDE;
-
- private:
-  JsEventRouter* parent_router_;
-
-  DISALLOW_COPY_AND_ASSIGN(JsDirectoryChangeListener);
-};
-
-}  // namespace browser_sync
-
-#endif  // CHROME_BROWSER_SYNC_JS_DIRECTORY_CHANGE_LISTENER_H_