Refactor the interface for the CrxDownloader to take a callback.

chrome/browser/component_updater/background_downloader_win.cc

 // Copyright 2013 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 "chrome/browser/component_updater/background_downloader_win.h"
 
 #include <atlbase.h>
 #include <atlcom.h>
 
 #include <functional>
@@ skipping 368 matching lines @@
   }
 
   return S_OK;
 }
 
 }  // namespace
 
 BackgroundDownloader::BackgroundDownloader(
     scoped_ptr<CrxDownloader> successor,
     net::URLRequestContextGetter* context_getter,
-    scoped_refptr<base::SequencedTaskRunner> task_runner,
-    const DownloadCallback& download_callback)
-    : CrxDownloader(successor.Pass(), download_callback),
+    scoped_refptr<base::SequencedTaskRunner> task_runner)
+    : CrxDownloader(successor.Pass()),
       context_getter_(context_getter),
       task_runner_(task_runner),
       is_completed_(false) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }
 
 BackgroundDownloader::~BackgroundDownloader() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   // The following objects have thread affinity and can't be destroyed on the
@@ skipping 342 matching lines @@
 }
 
 bool BackgroundDownloader::IsStuck() {
   const base::TimeDelta job_stuck_timeout(
       base::TimeDelta::FromMinutes(kJobStuckTimeoutMin));
   return job_stuck_begin_time_ + job_stuck_timeout < base::Time::Now();
 }
 
 }  // namespace component_updater