Automated IWYU fix for TaskRunner includes.

third_party/WebKit/Source/platform/scheduler/child/scheduler_tqm_delegate.h

 // 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.
 
 #ifndef THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_SCHEDULER_TQM_DELEGATE_H_
 #define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_SCHEDULER_TQM_DELEGATE_H_
 
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "platform/scheduler/base/task_queue_manager_delegate.h"
 
 namespace blink {
 namespace scheduler {
 
 class PLATFORM_EXPORT SchedulerTqmDelegate : public TaskQueueManagerDelegate {
  public:
   SchedulerTqmDelegate() {}
 
   // If the underlying task runner supports the concept of a default task
   // runner, the delegate should implement this function to redirect that task
   // runner to the scheduler.
   virtual void SetDefaultTaskRunner(
       scoped_refptr<base::SingleThreadTaskRunner> task_runner) = 0;
 
   // Similarly this method can be used to restore the original task runner when
   // the scheduler no longer wants to intercept tasks.
   virtual void RestoreDefaultTaskRunner() = 0;
 
  protected:
   ~SchedulerTqmDelegate() override {}
 
   DISALLOW_COPY_AND_ASSIGN(SchedulerTqmDelegate);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_SCHEDULER_TQM_DELEGATE_H_