[fsp] Improve performance for reading small chunks of data.

chrome/browser/local_discovery/storage/privet_filesystem_backend.cc

 // 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.
 
 #include "chrome/browser/local_discovery/storage/privet_filesystem_backend.h"
 
 #include <string>
 
 #include "chrome/browser/local_discovery/storage/privet_filesystem_async_util.h"
 #include "chrome/browser/local_discovery/storage/privet_filesystem_constants.h"
@@ skipping 70 matching lines @@
 
 bool PrivetFileSystemBackend::HasInplaceCopyImplementation(
     fileapi::FileSystemType type) const {
   return true;
 }
 
 scoped_ptr<webkit_blob::FileStreamReader>
 PrivetFileSystemBackend::CreateFileStreamReader(
     const fileapi::FileSystemURL& url,
     int64 offset,
+    int64 length,
     const base::Time& expected_modification_time,
     fileapi::FileSystemContext* context) const {
   return scoped_ptr<webkit_blob::FileStreamReader>();
 }
 
 scoped_ptr<fileapi::FileStreamWriter>
 PrivetFileSystemBackend::CreateFileStreamWriter(
     const fileapi::FileSystemURL& url,
     int64 offset,
     fileapi::FileSystemContext* context) const {
   return scoped_ptr<fileapi::FileStreamWriter>();
 }
 
 }  // namespace local_discovery