Revert of [cherrypick] Fix computation of runtime for throttled tasks

components/scheduler/renderer/throttled_time_domain.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_RENDERER_THROTTLED_TIME_DOMAIN_H_
-#define COMPONENTS_SCHEDULER_RENDERER_THROTTLED_TIME_DOMAIN_H_
-
-#include "base/macros.h"
-#include "components/scheduler/base/virtual_time_domain.h"
-
-namespace scheduler {
-
-// A time domain that's mostly a VirtualTimeDomain except that real time is used
-// when computing the delayed runtime.
-class SCHEDULER_EXPORT ThrottledTimeDomain : public VirtualTimeDomain {
- public:
-  ThrottledTimeDomain(TimeDomain::Observer* observer,
-                      base::TickClock* tick_clock);
-  ~ThrottledTimeDomain() override;
-
-  // TimeDomain implementation:
-  base::TimeTicks ComputeDelayedRunTime(base::TimeTicks time_domain_now,
-                                        base::TimeDelta delay) const override;
-  const char* GetName() const override;
-
- private:
-  base::TickClock* const tick_clock_;  // NOT OWNED
-
-  DISALLOW_COPY_AND_ASSIGN(ThrottledTimeDomain);
-};
-
-}  // namespace scheduler
-
-#endif  // COMPONENTS_SCHEDULER_RENDERER_THROTTLED_TIME_DOMAIN_H_