Chrome 56 introduces a commendable optimization to throttle background tabs' timers.

When idle, your application's timers may be delayed for minutes. Aside from terrible hacks like playing zero-volume sounds, you have no control over this. Avoiding expensive CPU work is not a panacea; that some applications must do significant work in the background, including syncing data, reading delta streams, and massaging said data to determine whether or not to alert the user.

A companion extension to uBlock Origin: to gain ability to foil early anti-user mechanisms working around content blockers or even a browser privacy settings.