(reland) Adds TimeDomains to the TaskQueueManager

components/scheduler/base/lazy_now.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_BASE_LAZY_NOW_H_
-#define COMPONENTS_SCHEDULER_BASE_LAZY_NOW_H_
-
-#include "base/time/time.h"
-
-namespace base {
-class TickClock;
-}
-
-namespace scheduler {
-namespace internal {
-
-// Now() is somewhat expensive so it makes sense not to call Now() unless we
-// really need to.
-class LazyNow {
- public:
-  explicit LazyNow(base::TimeTicks now) : tick_clock_(nullptr), now_(now) {
-    DCHECK(!now.is_null());
-  }
-
-  explicit LazyNow(base::TickClock* tick_clock) : tick_clock_(tick_clock) {}
-
-  base::TimeTicks Now();
-
- private:
-  base::TickClock* tick_clock_;  // NOT OWNED
-  base::TimeTicks now_;
-};
-
-}  // namespace internal
-}  // namespace scheduler
-
-#endif  // COMPONENTS_SCHEDULER_BASE_LAZY_NOW_H_