Trace where timers were scheduled in Blink

Source/core/html/track/vtt/VTTRegion.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 434 matching lines @@
 }
 
 void VTTRegion::startTimer()
 {
     WTF_LOG(Media, "VTTRegion::startTimer");
 
     if (m_scrollTimer.isActive())
         return;
 
     double duration = isScrollingRegion() ? scrollTime : 0;
-    m_scrollTimer.startOneShot(duration);
+    m_scrollTimer.startOneShot(duration, FROM_HERE);
 }
 
 void VTTRegion::stopTimer()
 {
     WTF_LOG(Media, "VTTRegion::stopTimer");
 
     if (m_scrollTimer.isActive())
         m_scrollTimer.stop();
 }
 
 void VTTRegion::scrollTimerFired(Timer<VTTRegion>*)
 {
     WTF_LOG(Media, "VTTRegion::scrollTimerFired");
 
     stopTimer();
     displayLastVTTCueBox();
 }
 
 } // namespace WebCore