Revert of Move throttling of background timers into the renderer scheduler

third_party/WebKit/Source/core/frame/DOMTimer.h

 /*
  * Copyright (C) 2008 Apple 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 34 matching lines @@
 public:
     // Creates a new timer owned by the ExecutionContext, starts it and returns its ID.
     static int install(ExecutionContext*, PassOwnPtrWillBeRawPtr<ScheduledAction>, int timeout, bool singleShot);
     static void removeByID(ExecutionContext*, int timeoutID);
 
     ~DOMTimer() override;
 
     // ActiveDOMObject
     void stop() override;
 
+    // The following are essentially constants. All intervals are in seconds.
+    static double hiddenPageAlignmentInterval();
+    static double visiblePageAlignmentInterval();
+
     // Eager finalization is needed to promptly stop this Timer object.
     // Otherwise timer events might fire at an object that's slated for destruction
     // (when lazily swept), but some of its members (m_action) may already have
     // been finalized & must not be accessed.
     EAGERLY_FINALIZE();
     DECLARE_VIRTUAL_TRACE();
 
     void disposeTimer();
 
 private:
     friend class DOMTimerCoordinator; // For create().
 
     static PassRefPtrWillBeRawPtr<DOMTimer> create(ExecutionContext* context, PassOwnPtrWillBeRawPtr<ScheduledAction> action, int timeout, bool singleShot, int timeoutID)
     {
         return adoptRefWillBeNoop(new DOMTimer(context, action, timeout, singleShot, timeoutID));
     }
 
     DOMTimer(ExecutionContext*, PassOwnPtrWillBeRawPtr<ScheduledAction>, int interval, bool singleShot, int timeoutID);
     void fired() override;
 
+    // Retuns timer fire time rounded to the next multiple of timer alignment interval.
+    double alignedFireTime(double) const override;
+
     WebTaskRunner* timerTaskRunner() override;
 
     int m_timeoutID;
     int m_nestingLevel;
     OwnPtrWillBeMember<ScheduledAction> m_action;
     RefPtr<UserGestureToken> m_userGestureToken;
 };
 
 } // namespace blink
 
 #endif // DOMTimer_h