Move blink scheduler implementation into a component

content/child/scheduler/null_idle_task_runner.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 CONTENT_CHILD_SCHEDULER_NULL_IDLE_TASK_RUNNER_H_
-#define CONTENT_CHILD_SCHEDULER_NULL_IDLE_TASK_RUNNER_H_
-
-#include "content/child/scheduler/single_thread_idle_task_runner.h"
-
-namespace content {
-
-class NullIdleTaskRunner : public SingleThreadIdleTaskRunner {
- public:
-  NullIdleTaskRunner();
-  void PostIdleTask(const tracked_objects::Location& from_here,
-                    const IdleTask& idle_task) override;
-
-  void PostNonNestableIdleTask(
-      const tracked_objects::Location& from_here,
-      const IdleTask& idle_task) override;
-
-  void PostIdleTaskAfterWakeup(
-      const tracked_objects::Location& from_here,
-      const IdleTask& idle_task) override;
-
- protected:
-  ~NullIdleTaskRunner() override;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(NullIdleTaskRunner);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_CHILD_SCHEDULER_NULL_IDLE_TASK_RUNNER_H_