Automated IWYU fix for TaskRunner includes.

gin/isolate_holder.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 "gin/public/isolate_holder.h"
 
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <memory>
 #include <utility>
 
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "base/sys_info.h"
 #include "gin/debug_impl.h"
 #include "gin/function_template.h"
 #include "gin/per_isolate_data.h"
 #include "gin/run_microtasks_observer.h"
 #include "gin/v8_initializer.h"
 #include "gin/v8_isolate_memory_dump_provider.h"
 
 namespace gin {
 
@@ skipping 82 matching lines @@
   task_observer_.reset();
 }
 
 void IsolateHolder::EnableIdleTasks(
     std::unique_ptr<V8IdleTaskRunner> idle_task_runner) {
   DCHECK(isolate_data_.get());
   isolate_data_->EnableIdleTasks(std::move(idle_task_runner));
 }
 
 }  // namespace gin