scheduler: Move the Blink scheduler into Blink

components/scheduler/base/long_task_tracker.h

-// Copyright 2016 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_BASE_LONG_TASK_TRACKER_H_
-#define COMPONENTS_SCHEDULER_BASE_LONG_TASK_TRACKER_H_
-
-#include <vector>
-
-#include "base/macros.h"
-#include "base/time/time.h"
-#include "components/scheduler/scheduler_export.h"
-
-namespace scheduler {
-
-// Records and reports long task times, above the threshold.
-// The threshold is set to 50ms in the implementation.
-class SCHEDULER_EXPORT LongTaskTracker {
- public:
-  using LongTaskTiming =
-      std::vector<std::pair<base::TimeTicks, base::TimeDelta>>;
-
-  LongTaskTracker();
-  ~LongTaskTracker();
-
-  LongTaskTiming GetLongTaskTiming();
-  void RecordLongTask(base::TimeTicks startTime,
-                      base::TimeDelta duration);
-
- private:
-  friend class LongTaskTrackerTest;
-
-  LongTaskTiming long_task_times_;
-
-  DISALLOW_COPY_AND_ASSIGN(LongTaskTracker);
-};
-
-}  // namespace scheduler
-
-#endif  // COMPONENTS_SCHEDULER_BASE_LONG_TASK_TRACKER_H_