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

webkit/browser/blob/blob_url_request_job.cc

Index: webkit/browser/blob/blob_url_request_job.cc
diff --git a/webkit/browser/blob/blob_url_request_job.cc b/webkit/browser/blob/blob_url_request_job.cc
index c4725a362277090f39a6bae2861c7b8a5212ca65..67a6bddcea2ae596ffb1637e3d5aa6b67e7c648a 100644
--- a/webkit/browser/blob/blob_url_request_job.cc
+++ b/webkit/browser/blob/blob_url_request_job.cc
@@ -4,7 +4,10 @@
 
 #include "webkit/browser/blob/blob_url_request_job.h"
 
+#include <algorithm>
 #include <limits>
+#include <string>
+#include <vector>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
@@ -577,6 +580,7 @@ void BlobURLRequestJob::CreateFileStreamReader(size_t index,
                                              file_system_context_->CrackURL(
                                                  item.filesystem_url())),
                                          item.offset() + additional_offset,
+                                         item.length() - additional_offset,
                                          item.expected_modification_time())
                    .release();
       break;