components/scheduler/child/lazy_now.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_SCHEDULER_CHILD_LAZY_NOW_H_
   6 #define COMPONENTS_SCHEDULER_CHILD_LAZY_NOW_H_
   7
   8 #include "base/time/time.h"
   9
  10 namespace scheduler {
  11 class TaskQueueManager;
  12
  13 namespace internal {
  14
  15 // Now() is somewhat expensive so it makes sense not to call Now() unless we
  16 // really need to.
  17 class LazyNow {
  18  public:
  19   explicit LazyNow(base::TimeTicks now)
  20       : task_queue_manager_(nullptr), now_(now) {
  21     DCHECK(!now.is_null());
  22   }
  23
  24   explicit LazyNow(TaskQueueManager* task_queue_manager)
  25       : task_queue_manager_(task_queue_manager) {}
  26
  27   base::TimeTicks Now();
  28
  29  private:
  30   TaskQueueManager* task_queue_manager_;  // NOT OWNED
  31   base::TimeTicks now_;
  32 };
  33
  34 }  // namespace internal
  35 }  // namespace scheduler
  36
  37 #endif  // COMPONENTS_SCHEDULER_CHILD_LAZY_NOW_H_