[fsp] Introduce BufferingFileStreamReader to read files in bigger chunks.

chrome/browser/chromeos/file_system_provider/fileapi/file_stream_reader.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_FILE_STREAM_READER_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_READER_H_
 
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "webkit/browser/blob/file_stream_reader.h"
 #include "webkit/browser/fileapi/file_system_url.h"
 
-namespace fileapi {
-class AsyncFileUtil;
-}  // namespace fileapi
-
 namespace chromeos {
 namespace file_system_provider {
 
 class ProvidedFileSystemInterface;
 
 // Implements a streamed file reader. It is lazily initialized by the first call
 // to Read().
 class FileStreamReader : public webkit_blob::FileStreamReader {
  public:
   typedef base::Callback<
@@ skipping 66 matching lines @@
   int file_handle_;
 
   base::WeakPtrFactory<FileStreamReader> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(FileStreamReader);
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_FILEAPI_FILE_STREAM_READER_H_