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

webkit/browser/fileapi/plugin_private_file_system_backend.cc

 // 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.
 
 #include "webkit/browser/fileapi/plugin_private_file_system_backend.h"
 
 #include <map>
 
 #include "base/stl_util.h"
 #include "base/synchronization/lock.h"
@@ skipping 174 matching lines @@
 
 bool PluginPrivateFileSystemBackend::HasInplaceCopyImplementation(
     fileapi::FileSystemType type) const {
   return false;
 }
 
 scoped_ptr<webkit_blob::FileStreamReader>
 PluginPrivateFileSystemBackend::CreateFileStreamReader(
     const FileSystemURL& url,
     int64 offset,
+    int64 length,
     const base::Time& expected_modification_time,
     FileSystemContext* context) const {
   return scoped_ptr<webkit_blob::FileStreamReader>();
 }
 
 scoped_ptr<FileStreamWriter>
 PluginPrivateFileSystemBackend::CreateFileStreamWriter(
     const FileSystemURL& url,
     int64 offset,
     FileSystemContext* context) const {
@@ skipping 92 matching lines @@
     FileSystemType type) const {
   return NULL;
 }
 
 ObfuscatedFileUtil* PluginPrivateFileSystemBackend::obfuscated_file_util() {
   return static_cast<ObfuscatedFileUtil*>(
       static_cast<AsyncFileUtilAdapter*>(file_util_.get())->sync_file_util());
 }
 
 }  // namespace fileapi