scheduler: Implement WebFrameScheduler and WebPageScheduler

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

 /*
  * 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 182 matching lines @@
 
         if (fireTime - alignedTimeRoundedDown < minimumInterval)
             return alignedTimeRoundedDown;
 
         return alignedTimeRoundedUp;
     }
 
     return fireTime;
 }
 
+WebTaskRunner* DOMTimer::timerTaskRunner()
+{
+    return executionContext()->timers()->timerTaskRunner();
+}
+
 DEFINE_TRACE(DOMTimer)
 {
     visitor->trace(m_action);
     SuspendableTimer::trace(visitor);
 }
 
 } // namespace blink