Move a subset of chrome/browser/chromeos/drive into components/drive

chrome/browser/chromeos/drive/local_file_reader.h

-// Copyright 2013 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_DRIVE_LOCAL_FILE_READER_H_
-#define CHROME_BROWSER_CHROMEOS_DRIVE_LOCAL_FILE_READER_H_
-
-#include "base/basictypes.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/weak_ptr.h"
-#include "net/base/completion_callback.h"
-#include "net/base/file_stream.h"
-
-namespace base {
-class FilePath;
-class SequencedTaskRunner;
-}  // namespace base
-
-namespace net {
-class IOBuffer;
-}  // namespace net
-
-namespace drive {
-namespace util {
-
-// This is simple local file reader implementation focusing on Drive's use
-// case. All the operations run on |sequenced_task_runner| asynchronously and
-// the result will be notified to the caller via |callback|s on the caller's
-// thread.
-class LocalFileReader {
- public:
-  explicit LocalFileReader(base::SequencedTaskRunner* sequenced_task_runner);
-  ~LocalFileReader();
-
-  // Opens the file at |file_path|. The initial position of the read will be
-  // at |offset| from the beginning of the file.
-  // Upon completion, |callback| will be called.
-  // |callback| must not be null.
-  void Open(const base::FilePath& file_path,
-            int64 offset,
-            const net::CompletionCallback& callback);
-
-  // Reads the file and copies the data into |buffer|. |buffer_length|
-  // is the length of |buffer|.
-  // Upon completion, |callback| will be called with the result.
-  // |callback| must not be null.
-  void Read(net::IOBuffer* buffer,
-            int buffer_length,
-            const net::CompletionCallback& callback);
-
- private:
-  void DidOpen(const net::CompletionCallback& callback,
-               int64 offset,
-               int error);
-  void DidSeek(const net::CompletionCallback& callback,
-               int64 offset,
-               int64 error);
-
-  net::FileStream file_stream_;
-
-  // Note: This should remain the last member so it'll be destroyed and
-  // invalidate the weak pointers before any other members are destroyed.
-  base::WeakPtrFactory<LocalFileReader> weak_ptr_factory_;
-  DISALLOW_COPY_AND_ASSIGN(LocalFileReader);
-};
-
-}  // namespace util
-}  // namespace drive
-
-#endif  // CHROME_BROWSER_CHROMEOS_DRIVE_LOCAL_FILE_READER_H_