scheduler: Move the Blink scheduler into Blink

components/scheduler/renderer/idle_time_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_IDLE_TIME_ESTIMATOR_H_
-#define COMPONENTS_SCHEDULER_RENDERER_IDLE_TIME_ESTIMATOR_H_
-
-#include "base/macros.h"
-#include "base/message_loop/message_loop.h"
-#include "base/time/tick_clock.h"
-#include "cc/base/rolling_time_delta_history.h"
-#include "components/scheduler/base/task_queue.h"
-#include "components/scheduler/scheduler_export.h"
-
-namespace scheduler {
-
-// Estimates how much idle time there is available.  Ignores nested tasks.
-class SCHEDULER_EXPORT IdleTimeEstimator
-    : public base::MessageLoop::TaskObserver {
- public:
-  IdleTimeEstimator(const scoped_refptr<TaskQueue>& compositor_task_runner,
-                    base::TickClock* time_source,
-                    int sample_count,
-                    double estimation_percentile);
-
-  ~IdleTimeEstimator() override;
-
-  // Expected Idle time is defined as: |compositor_frame_interval| minus
-  // expected compositor task duration.
-  base::TimeDelta GetExpectedIdleDuration(
-      base::TimeDelta compositor_frame_interval) const;
-
-  void DidCommitFrameToCompositor();
-
-  void Clear();
-
-  // TaskObserver implementation:
-  void WillProcessTask(const base::PendingTask& pending_task) override;
-  void DidProcessTask(const base::PendingTask& pending_task) override;
-
- private:
-  scoped_refptr<TaskQueue> compositor_task_runner_;
-  cc::RollingTimeDeltaHistory per_frame_compositor_task_runtime_;
-  base::TickClock* time_source_;  // NOT OWNED
-  double estimation_percentile_;
-
-  base::TimeTicks task_start_time_;
-  base::TimeTicks prev_commit_time_;
-  base::TimeDelta cumulative_compositor_runtime_;
-  int nesting_level_;
-  bool did_commit_;
-
-  DISALLOW_COPY_AND_ASSIGN(IdleTimeEstimator);
-};
-
-}  // namespace scheduler
-
-#endif  // COMPONENTS_SCHEDULER_RENDERER_IDLE_TIME_ESTIMATOR_H_