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

webkit/browser/fileapi/file_system_context.cc

Index: webkit/browser/fileapi/file_system_context.cc
diff --git a/webkit/browser/fileapi/file_system_context.cc b/webkit/browser/fileapi/file_system_context.cc
index 5d44499690346ed3ec9d66e4b1f61d1f8d34c688..bab9f9cb6a06797831b4b88cb1c324f786dde969 100644
--- a/webkit/browser/fileapi/file_system_context.cc
+++ b/webkit/browser/fileapi/file_system_context.cc
@@ -421,6 +421,7 @@ void FileSystemContext::DeleteFileSystem(
 scoped_ptr<storage::FileStreamReader> FileSystemContext::CreateFileStreamReader(
     const FileSystemURL& url,
     int64 offset,
+    int64 length,
     const base::Time& expected_modification_time) {
   if (!url.is_valid())
     return scoped_ptr<storage::FileStreamReader>();
@@ -428,7 +429,7 @@ scoped_ptr<storage::FileStreamReader> FileSystemContext::CreateFileStreamReader(
   if (!backend)
     return scoped_ptr<storage::FileStreamReader>();
   return backend->CreateFileStreamReader(
-      url, offset, expected_modification_time, this);
+      url, offset, length, expected_modification_time, this);
 }
 
 scoped_ptr<FileStreamWriter> FileSystemContext::CreateFileStreamWriter(