Automated IWYU fix for TaskRunner includes.

net/log/file_net_log_observer.cc

 // Copyright 2016 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 "net/log/file_net_log_observer.h"
 
 #include <limits>
 #include <memory>
 #include <queue>
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/json/json_writer.h"
 #include "base/logging.h"
+#include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread.h"
 #include "base/values.h"
 #include "net/log/net_log_capture_mode.h"
 #include "net/log/net_log_entry.h"
 #include "net/log/net_log_util.h"
 #include "net/url_request/url_request_context.h"
 
 namespace {
@@ skipping 500 matching lines @@
 void FileNetLogObserver::UnboundedFileWriter::DeleteAllFiles() {
   DCHECK(task_runner_->RunsTasksOnCurrentThread());
 
   // Reset |file_| to release the file handle so base::DeleteFile can
   // safely access it.
   file_.reset();
   base::DeleteFile(file_path_, false);
 }
 
 }  // namespace net