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

storage/browser/fileapi/file_system_context.cc

Index: storage/browser/fileapi/file_system_context.cc
diff --git a/storage/browser/fileapi/file_system_context.cc b/storage/browser/fileapi/file_system_context.cc
index f42e11ae2baa4225d8eaaeb421d05392f3b2f434..7c93540e3c1b1fb094ce4d026f884152a439bc21 100644
--- a/storage/browser/fileapi/file_system_context.cc
+++ b/storage/browser/fileapi/file_system_context.cc
@@ -437,6 +437,7 @@ void FileSystemContext::DeleteFileSystem(
 scoped_ptr<storage::FileStreamReader> FileSystemContext::CreateFileStreamReader(
     const FileSystemURL& url,
     int64 offset,
+    int64 max_bytes_to_read,
     const base::Time& expected_modification_time) {
   if (!url.is_valid())
     return scoped_ptr<storage::FileStreamReader>();
@@ -444,7 +445,7 @@ scoped_ptr<storage::FileStreamReader> FileSystemContext::CreateFileStreamReader(
   if (!backend)
     return scoped_ptr<storage::FileStreamReader>();
   return backend->CreateFileStreamReader(
-      url, offset, expected_modification_time, this);
+      url, offset, max_bytes_to_read, expected_modification_time, this);
 }
 
 scoped_ptr<FileStreamWriter> FileSystemContext::CreateFileStreamWriter(