[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 0df0a1dfced0ce0301d6cd098540311e0f717675..a3c191e9c6e15b337373b85f1a1335b4b114c2aa 100644
--- a/webkit/browser/fileapi/file_system_context.cc
+++ b/webkit/browser/fileapi/file_system_context.cc
@@ -423,6 +423,7 @@ scoped_ptr<webkit_blob::FileStreamReader>
 FileSystemContext::CreateFileStreamReader(
     const FileSystemURL& url,
     int64 offset,
+    int64 length,
     const base::Time& expected_modification_time) {
   if (!url.is_valid())
     return scoped_ptr<webkit_blob::FileStreamReader>();
@@ -430,7 +431,7 @@ FileSystemContext::CreateFileStreamReader(
   if (!backend)
     return scoped_ptr<webkit_blob::FileStreamReader>();
   return backend->CreateFileStreamReader(
-      url, offset, expected_modification_time, this);
+      url, offset, length, expected_modification_time, this);
 }
 
 scoped_ptr<FileStreamWriter> FileSystemContext::CreateFileStreamWriter(