Refactor MHTMLGenerator to allow getting sending the data to a file descriptor.

content/browser/download/save_package.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/save_package.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/file_util.h"
@@ skipping 345 matching lines @@
                                        save_source);
     // Add this item to waiting list.
     waiting_item_queue_.push(save_item);
     all_save_items_count_ = 1;
     download_->SetTotalBytes(1);
 
     DoSavingProcess();
   }
 }
 
-void SavePackage::OnMHTMLGenerated(const base::FilePath& path, int64 size) {
+void SavePackage::OnMHTMLGenerated(int64 size) {
   if (size <= 0) {
     Cancel(false);
     return;
   }
   wrote_to_completed_file_ = true;
 
   // Hack to avoid touching download_ after user cancel.
   // TODO(rdsmith/benjhayden): Integrate canceling on DownloadItem
   // with SavePackage flow.
   if (download_->GetState() == DownloadItem::IN_PROGRESS) {
@@ skipping 1069 matching lines @@
 
 void SavePackage::FinalizeDownloadEntry() {
   DCHECK(download_);
   DCHECK(download_manager_);
 
   download_manager_->OnSavePackageSuccessfullyFinished(download_);
   StopObservation();
 }
 
 }  // namespace content