We want to be able to respond to spikes in client errors better. While debugging T208605 it became evident that knowing the browser family and domain would have helped us isolate this error a little quicker.
mw.track( 'counter.MediaWiki.minerva.WebClientError', 1 );
we will do
mw.track( 'counter.MediaWiki.minerva.WebClientError.<project>.<browser family>', 1 );
We can get project from mw.config.get("wgDBname")
browser family should be one of Firefox, Safari, Chrome, Opera or UC. The more explicit the better. Let's talk about options there.