Probably only when show-gecko-platform-data is on. Would like to see a graph of the avg time between posting a runnable to the main thread's event queue and when the event loop runs that runnable. I'm not sure if the SPS profiler already has this information, but it shouldn't be too hard to add it.
Chrome has something similar behind an experimental pref (hit shift 6 times), "Timeline Flow Events". May or may not make it to release in this form. http://i.imgur.com/bFWn3ZK.png
Triaging. Filter on ADRENOCORTICOTROPIC (yes).