[Downloads] Rework how hashes are calculated for download files.

content/browser/download/download_file_factory.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 "content/browser/download/download_file_factory.h"
 
 #include <utility>
 
 #include "content/browser/download/download_file_impl.h"
 
 namespace content {
 
 DownloadFileFactory::~DownloadFileFactory() {}
 
 DownloadFile* DownloadFileFactory::CreateFile(
-    const DownloadSaveInfo& save_info,
+    scoped_ptr<DownloadSaveInfo> save_info,
     const base::FilePath& default_downloads_directory,
-    const GURL& url,
-    const GURL& referrer_url,
-    bool calculate_hash,
-    base::File file,
     scoped_ptr<ByteStreamReader> byte_stream,
     const net::BoundNetLog& bound_net_log,
     base::WeakPtr<DownloadDestinationObserver> observer) {
-  return new DownloadFileImpl(save_info, default_downloads_directory, url,
-                              referrer_url, calculate_hash, std::move(file),
-                              std::move(byte_stream), bound_net_log, observer);
+  return new DownloadFileImpl(std::move(save_info),
+                              default_downloads_directory,
+                              std::move(byte_stream),
+                              bound_net_log,
+                              observer);
 }
 
 }  // namespace content