Revert of Move throttling of background timers into the renderer scheduler

third_party/WebKit/Source/platform/Timer.h

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 43 matching lines @@
     void startOneShot(double interval, const WebTraceLocation& caller)
     {
         start(interval, 0, caller);
     }
 
     void stop();
     bool isActive() const;
     const WebTraceLocation& location() const { return m_location; }
 
     double nextFireInterval() const;
+    double nextUnalignedFireInterval() const;
     double repeatInterval() const { return m_repeatInterval; }
 
     void augmentRepeatInterval(double delta) {
         double now = monotonicallyIncreasingTime();
         setNextFireTime(now, m_nextFireTime - now + delta);
         m_repeatInterval += delta;
     }
 
+    void didChangeAlignmentInterval(double now);
+
     struct PLATFORM_EXPORT Comparator {
         bool operator()(const TimerBase* a, const TimerBase* b) const;
     };
 
 private:
     virtual void fired() = 0;
 
     virtual WebTaskRunner* timerTaskRunner();
 
     NO_LAZY_SWEEP_SANITIZE_ADDRESS
@@ skipping 29 matching lines @@
         void cancel()
         {
             m_timer = nullptr;
         }
 
     private:
         TimerBase* m_timer; // NOT OWNED
     };
 
     double m_nextFireTime; // 0 if inactive
+    double m_unalignedNextFireTime; // m_nextFireTime not considering alignment interval
     double m_repeatInterval; // 0 if not repeating
     WebTraceLocation m_location;
     CancellableTimerTask* m_cancellableTimerTask; // NOT OWNED
     WebScheduler* m_webScheduler; // Not owned.
 
 #if ENABLE(ASSERT)
     ThreadIdentifier m_thread;
 #endif
 
     friend class ThreadTimers;
@@ skipping 53 matching lines @@
 NO_LAZY_SWEEP_SANITIZE_ADDRESS
 inline bool TimerBase::isActive() const
 {
     ASSERT(m_thread == currentThread());
     return m_cancellableTimerTask;
 }
 
 } // namespace blink
 
 #endif // Timer_h