https://bugs.freedesktop.org/show_bug.cgi?id=82055
--- Comment #6 from Michel Dänzer michel@daenzer.net --- (In reply to comment #4)
Yes, Twitch, like YouTube, requires Flash.
Actually, YouTube doesn't require Flash, at least not for many videos.
Does doing anything in particular trigger it in MediathekView?
Sort of: just starting is enough. You get the grey window background at below average speed and then it takes seconds until the UI elements are drawn (list of shows, filter boxes, buttons). Afterwards you can trigger a new CPU spike by trying to click anything or even better on each keypress/character input into the title filter field on the left.
I can reproduce this with glamor from xserver 1.16.0, but not from current xserver Git master. So at least that part is already fixed.