iwyu: Use callback_old.h where appropriate, part 2.

chrome/browser/download/download_safe_browsing_client.h

 // 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.
 
 #ifndef CHROME_BROWSER_DOWNLOAD_DOWNLOAD_SAFE_BROWSING_CLIENT_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_SAFE_BROWSING_CLIENT_H_
 #pragma once
 
-#include "base/callback.h"
+#include "base/callback_old.h"
 #include "base/memory/ref_counted.h"
 #include "base/time.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
 
 struct DownloadCreateInfo;
 
 // This is a helper class used by DownloadManager to check a download URL with
 // SafeBrowsingService. The client is refcounted and will be  released once
 // there is no reference to it.
 // Usage:
@@ skipping 81 matching lines @@
   std::vector<GURL> url_chain_;
   GURL referrer_url_;
 
   // When a safebrowsing check starts, for stats purpose.
   base::TimeTicks start_time_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadSBClient);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_SAFE_BROWSING_CLIENT_H_