scheduler: Implement WebFrameScheduler and WebPageScheduler

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 61 matching lines @@
     {
         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