Trace where timers were scheduled in Blink

Source/modules/encryptedmedia/MediaKeySession.cpp

 /*
  * Copyright (C) 2013 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 107 matching lines @@
         return;
     }
 
     // 2. If the session is not in the PENDING state, throw an INVALID_STATE_ERR.
     // FIXME: Implement states in MediaKeySession.
 
     // 3. Schedule a task to handle the call, providing response.
     m_pendingActions.append(PendingAction::CreatePendingUpdate(response));
 
     if (!m_actionTimer.isActive())
-        m_actionTimer.startOneShot(0);
+        m_actionTimer.startOneShot(0, FROM_HERE);
 }
 
 void MediaKeySession::release(ExceptionState& exceptionState)
 {
     WTF_LOG(Media, "MediaKeySession::release");
     ASSERT(!m_isClosed);
 
     // From <https://dvcs.w3.org/hg/html-media/raw-file/default/encrypted-media/encrypted-media.html#dom-release>:
     // The release() method must run the following steps:
     // 1. If the state of the MediaKeySession is CLOSED then abort these steps.
     // 2. If the state of the MediaKeySession is ERROR, throw an INVALID_STATE_ERR
     //    exception and abort these steps.
     // FIXME: Implement states in MediaKeySession.
 
     // 3. Schedule a task to handle the call.
     m_pendingActions.append(PendingAction::CreatePendingRelease());
 
     if (!m_actionTimer.isActive())
-        m_actionTimer.startOneShot(0);
+        m_actionTimer.startOneShot(0, FROM_HERE);
 }
 
 void MediaKeySession::actionTimerFired(Timer<MediaKeySession>*)
 {
     ASSERT(m_pendingActions.size());
 
     while (!m_pendingActions.isEmpty()) {
         OwnPtr<PendingAction> pendingAction(m_pendingActions.takeFirst());
 
         switch (pendingAction->type) {
@@ skipping 107 matching lines @@
     m_session.clear();
     m_isClosed = true;
 
     if (m_actionTimer.isActive())
         m_actionTimer.stop();
     m_pendingActions.clear();
     m_asyncEventQueue->close();
 }
 
 }