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

webkit/browser/blob/blob_url_request_job.cc

 // Copyright (c) 2012 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 "webkit/browser/blob/blob_url_request_job.h"
 
+#include <algorithm>
 #include <limits>
+#include <string>
+#include <vector>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_util_proxy.h"
 #include "base/format_macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 552 matching lines @@
           item.path(),
           item.offset() + additional_offset,
           item.expected_modification_time());
       break;
     case BlobData::Item::TYPE_FILE_FILESYSTEM:
       reader = file_system_context_->CreateFileStreamReader(
                                          storage::FileSystemURL(
                                              file_system_context_->CrackURL(
                                                  item.filesystem_url())),
                                          item.offset() + additional_offset,
+                                         item.length() - additional_offset,
                                          item.expected_modification_time())
                    .release();
       break;
     default:
       NOTREACHED();
   }
   DCHECK(reader);
   index_to_reader_[index] = reader;
 }
 
 }  // namespace storage