process.nextTick polyfill is slow when tab is unfocused

[satazor]

The nextTick polyfill is supplied by https://github.com/defunctzombie/node-process/blob/master/browser.js which uses timers. See: defunctzombie/node-process#86.

Because timers are often throttled when a tab is not active to improve battery life, they only run at 1Hz (once every second). This has a drastic performance impact in those scenarios.

It seems that the author won't change this for the time being, see: webtorrent/webtorrent#1568 (comment)

It would be cool to just map nextTick to setImmediate, as we are already providing that polyfill.