Move blink scheduler implementation into a component

content/renderer/scheduler/deadline_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_RENDERER_SCHEDULER_DEADLINE_TASK_RUNNER_H_
-#define CONTENT_RENDERER_SCHEDULER_DEADLINE_TASK_RUNNER_H_
-
-#include "base/callback.h"
-#include "base/macros.h"
-#include "base/memory/weak_ptr.h"
-#include "base/single_thread_task_runner.h"
-#include "base/time/time.h"
-#include "content/child/scheduler/cancelable_closure_holder.h"
-#include "content/common/content_export.h"
-
-namespace content {
-
-// Runs a posted task at latest by a given deadline, but possibly sooner.
-class CONTENT_EXPORT DeadlineTaskRunner {
- public:
-  DeadlineTaskRunner(const base::Closure& callback,
-                     scoped_refptr<base::SingleThreadTaskRunner> task_runner);
-
-  ~DeadlineTaskRunner();
-
-  // If there is no outstanding task then a task is posted to run after |delay|.
-  // If there is an outstanding task which is scheduled to run:
-  //   a) sooner - then this is a NOP.
-  //   b) later - then the outstanding task is cancelled and a new task is
-  //              posted to run after |delay|.
-  //
-  // Once the deadline task has run, we reset.
-  void SetDeadline(const tracked_objects::Location& from_here,
-                   base::TimeDelta delay,
-                   base::TimeTicks now);
-
- private:
-  void RunInternal();
-
-  CancelableClosureHolder cancelable_run_internal_;
-  base::Closure callback_;
-  base::TimeTicks deadline_;
-  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
-
-  DISALLOW_COPY_AND_ASSIGN(DeadlineTaskRunner);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_SCHEDULER_DEADLINE_TASK_RUNNER_H_