I was investigating why my profile is having difficulties getting bookmarks backups. I started logging idle service behavior through this snippet of code in the browser console: let idle = Components.classes["@mozilla.org/widget/idleservice;1"].getService(Components.interfaces.nsIIdleService); [1,2,3,5,7,10].forEach(aTimeMin => { idle.addIdleObserver((undefined, aTopic) => { console.log(aTopic); if (aTopic == "idle") console.log(aTimeMin + " <= " + Math.round(idle.idleTime / 60000)) }, aTimeMin * 60) }) Looks like having irccloud open in a tab breaks idle, after 2 to 5 minutes (this is variable) I see an "active" event, so anything waiting for 10 or more minutes of idle is never executed. I don't think that content should _ever_ be able to modify the idle status of the browser. I didn't try to check which event caused by the page is enforcing the active status yet.

Since the idleservice has a OS specific implementations, I clarify this was reproduce on Win8.1

Cc-ing Roberto who is working on power consumption, as this may be related.

This is not a Firefox front-end bug, so not eligible for being in our backlog.

Kan-Ru said "While it's bad that content could affect idle status of the browser, I don't think it affects power consumption that much. The only downside is if we throttle some activities (animations, maybe?) when the browser is idle, it won't happen. But we are not throttling based on that currently so I suggest Power:P3."