Revert of [fsp] Add an initial AsyncFileUtil.

chrome/browser/chromeos/file_system_provider/fileapi/backend_delegate.h

-// 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.
-
-#ifndef CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_BACKEND_DELEGATE_H_
-#define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_BACKEND_DELEGATE_H_
-
-#include "base/basictypes.h"
-#include "base/memory/scoped_ptr.h"
-#include "chrome/browser/chromeos/fileapi/file_system_backend_delegate.h"
-
-namespace fileapi {
-class AsyncFileUtil;
-}  // namespace fileapi
-
-namespace chromeos {
-namespace file_system_provider {
-
-// Delegate implementation of the some methods in chromeos::FileSystemBackend
-// for provided file systems.
-class BackendDelegate : public chromeos::FileSystemBackendDelegate {
- public:
-  BackendDelegate();
-  virtual ~BackendDelegate();
-
-  // FileSystemBackend::Delegate overrides.
-  virtual fileapi::AsyncFileUtil* GetAsyncFileUtil(fileapi::FileSystemType type)
-      OVERRIDE;
-  virtual scoped_ptr<webkit_blob::FileStreamReader> CreateFileStreamReader(
-      const fileapi::FileSystemURL& url,
-      int64 offset,
-      const base::Time& expected_modification_time,
-      fileapi::FileSystemContext* context) OVERRIDE;
-  virtual scoped_ptr<fileapi::FileStreamWriter> CreateFileStreamWriter(
-      const fileapi::FileSystemURL& url,
-      int64 offset,
-      fileapi::FileSystemContext* context) OVERRIDE;
-
- private:
-  scoped_ptr<fileapi::AsyncFileUtil> async_file_util_;
-
-  DISALLOW_COPY_AND_ASSIGN(BackendDelegate);
-};
-
-}  // namespace file_system_provider
-}  // namespace chromeos
-
-#endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_BACKEND_DELEGATE_H_