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

content/public/test/test_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 "content/public/test/test_file_system_backend.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 217 matching lines @@
 
 bool TestFileSystemBackend::HasInplaceCopyImplementation(
     storage::FileSystemType type) const {
   return true;
 }
 
 scoped_ptr<storage::FileStreamReader>
 TestFileSystemBackend::CreateFileStreamReader(
     const FileSystemURL& url,
     int64 offset,
+    int64 length,
     const base::Time& expected_modification_time,
     FileSystemContext* context) const {
   return scoped_ptr<storage::FileStreamReader>(
       storage::FileStreamReader::CreateForFileSystemFile(
           context, url, offset, expected_modification_time));
 }
 
 scoped_ptr<storage::FileStreamWriter>
 TestFileSystemBackend::CreateFileStreamWriter(
     const FileSystemURL& url,
@@ skipping 13 matching lines @@
   return quota_util_->GetUpdateObservers(type);
 }
 
 void TestFileSystemBackend::AddFileChangeObserver(
     storage::FileChangeObserver* observer) {
   quota_util_->AddFileChangeObserver(
       storage::kFileSystemTypeTest, observer, quota_util_->task_runner());
 }
 
 }  // namespace content