Automated IWYU fix for TaskRunner includes.

content/browser/download/url_downloader.cc

 // Copyright 2015 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/url_downloader.h"
 
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/macros.h"
+#include "base/sequenced_task_runner.h"
 #include "base/threading/sequenced_task_runner_handle.h"
 #include "content/browser/byte_stream.h"
 #include "content/browser/download/download_create_info.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/browser/download_save_info.h"
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_errors.h"
@@ skipping 214 matching lines @@
 }
 
 void UrlDownloader::Destroy() {
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&UrlDownloader::Delegate::OnUrlDownloaderStopped, delegate_,
                  this));
 }
 
 }  // namespace content