Trace where timers were scheduled in Blink

Source/modules/notifications/NotificationCenter.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2012 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 106 matching lines @@
 
 NotificationCenter::NotificationRequestCallback::NotificationRequestCallback(NotificationCenter* center, PassOwnPtr<VoidCallback> callback)
     : m_notificationCenter(center)
     , m_timer(this, &NotificationCenter::NotificationRequestCallback::timerFired)
     , m_callback(callback)
 {
 }
 
 void NotificationCenter::NotificationRequestCallback::startTimer()
 {
-    m_timer.startOneShot(0);
+    m_timer.startOneShot(0, FROM_HERE);
 }
 
 void NotificationCenter::NotificationRequestCallback::timerFired(Timer<NotificationCenter::NotificationRequestCallback>*)
 {
     if (m_callback)
         m_callback->handleEvent();
     m_notificationCenter->requestTimedOut(this);
 }
 
 void NotificationCenter::NotificationRequestCallback::trace(Visitor* visitor)
 {
     visitor->trace(m_notificationCenter);
 }
 
 } // namespace WebCore
 
 #endif // ENABLE(LEGACY_NOTIFICATIONS)