DownloadManager intereface refactoring to allow cleaner DownloadItem unit tests.

content/browser/download/save_package.cc

 // Copyright (c) 2011 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_path.h"
@@ skipping 250 matching lines @@
 
   wait_state_ = START_PROCESS;
 
   // Initialize the request context and resource dispatcher.
   content::BrowserContext* browser_context = tab_contents()->browser_context();
   if (!browser_context) {
     NOTREACHED();
     return false;
   }
 
-  // Create the download item, and add ourself as an observer.
-  download_ = new DownloadItemImpl(download_manager_,
-                                   saved_main_file_path_,
-                                   page_url_,
-                                   browser_context->IsOffTheRecord(),
-                                   download_manager_->GetNextId());
-  download_->AddObserver(this);
-
-  // Transfer ownership to the download manager.
-  download_manager_->SavePageDownloadStarted(download_);
+  // The download manager keeps ownership but adds us as an observer.
+  download_ = download_manager_->CreateSavePackageDownloadItem(
+      saved_main_file_path_, page_url_,
+      browser_context->IsOffTheRecord(), this);
 
   // Check save type and process the save page job.
   if (save_type_ == SAVE_AS_COMPLETE_HTML) {
     // Get directory
     DCHECK(!saved_main_directory_path_.empty());
     GetAllSavableResourceLinksForCurrentPage();
   } else {
     wait_state_ = NET_FILES;
     SaveFileCreateInfo::SaveFileSource save_source = page_url_.SchemeIsFile() ?
         SaveFileCreateInfo::SAVE_FILE_FROM_FILE :
@@ skipping 999 matching lines @@
     StopObservation();
 }
 
 void SavePackage::FinalizeDownloadEntry() {
   DCHECK(download_);
   DCHECK(download_manager_);
 
   download_manager_->SavePageDownloadFinished(download_);
   StopObservation();
 }