scheduler: Move the Blink scheduler into Blink

components/scheduler/renderer/task_cost_estimator.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 COMPONENTS_SCHEDULER_RENDERER_TASK_COST_ESTIMATOR_H_
-#define COMPONENTS_SCHEDULER_RENDERER_TASK_COST_ESTIMATOR_H_
-
-#include "base/macros.h"
-#include "base/message_loop/message_loop.h"
-#include "base/time/time.h"
-#include "cc/base/rolling_time_delta_history.h"
-#include "components/scheduler/scheduler_export.h"
-
-namespace base {
-class TickClock;
-}
-
-namespace scheduler {
-
-// Estimates the cost of running tasks based on historical timing data.
-class SCHEDULER_EXPORT TaskCostEstimator
-    : public base::MessageLoop::TaskObserver {
- public:
-  TaskCostEstimator(base::TickClock* time_source,
-                    int sample_count,
-                    double estimation_percentile);
-  ~TaskCostEstimator() override;
-
-  base::TimeDelta expected_task_duration() const;
-
-  // TaskObserver implementation:
-  void WillProcessTask(const base::PendingTask& pending_task) override;
-  void DidProcessTask(const base::PendingTask& pending_task) override;
-
-  void Clear();
-
- private:
-  cc::RollingTimeDeltaHistory rolling_time_delta_history_;
-  base::TickClock* time_source_;  // NOT OWNED
-  int outstanding_task_count_;
-  double estimation_percentile_;
-  base::TimeTicks task_start_time_;
-  base::TimeDelta expected_task_duration_;
-
-  DISALLOW_COPY_AND_ASSIGN(TaskCostEstimator);
-};
-
-}  // namespace scheduler
-
-#endif  // COMPONENTS_SCHEDULER_RENDERER_TASK_COST_ESTIMATOR_H_