Add skeleton code to wire Local- and Remote- file sync services

chrome/browser/sync_file_system/local_change_processor.h

+// Copyright (c) 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.
+
+#ifndef CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_CHANGE_PROCESSOR_H_
+#define CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_CHANGE_PROCESSOR_H_
+
+#include "base/callback_forward.h"
+
+namespace fileapi {
+class FileChange;
+class FileChangeList;
+class FileSystemURL
+}
+
+namespace sync_file_system {
+
+// Represents an interface to process one local change and applies
+// it to the remote server.
+// This interface is to be implemented/backed by RemoteSyncFileService.
+class LocalChangeProcessor {
+ public:
+  typedef base::Callback<void(fileapi::SyncStatusCode status)> StatusCallback;
+
+  LocalChangeProcessor() {}
+  virtual ~LocalChangeProcessor() {}
+
+  // This is called to apply the local |change|. If the change type is
+  // ADD_OR_UPDATE for a file, |local_path| needs to point to a
+  // local file path that contains the latest file image.
+  virtual void ApplyLocalChange(
+      const fileapi::FileChange& change,
+      const FilePath& local_path,
+      const fileapi::FileSystemURL& url,
+      const StatusCallback& callback) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(LocalChangeProcessor);
+};
+
+}  // namespace sync_file_system
+
+#endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_CHANGE_PROCESSOR_H_