Automated IWYU fix for TaskRunner includes.

net/cert_net/cert_net_fetcher_impl.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.
 //
 // Overview
 //
 // The main entry point is CertNetFetcherImpl. This is an implementation of
 // CertNetFetcher that provides a service for fetching network requests.
 //
 // The interface for CertNetFetcher is synchronous, however allows
@@ skipping 48 matching lines @@
 #include "net/cert_net/cert_net_fetcher_impl.h"
 
 #include <tuple>
 #include <utility>
 
 #include "base/callback_helpers.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/numerics/safe_math.h"
+#include "base/single_thread_task_runner.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/timer/timer.h"
 #include "net/base/load_flags.h"
 #include "net/cert/cert_net_fetcher.h"
 #include "net/url_request/redirect_info.h"
 #include "net/url_request/url_request_context.h"
 
 // TODO(eroman): Add support for POST parameters.
 // TODO(eroman): Add controls for bypassing the cache.
@@ skipping 705 matching lines @@
   std::unique_ptr<AsyncCertNetFetcherImpl> impl_;
 };
 
 }  // namespace
 
 scoped_refptr<CertNetFetcher> CreateCertNetFetcher(URLRequestContext* context) {
   return make_scoped_refptr(new CertNetFetcherImpl(context));
 }
 
 }  // namespace net