Xorg at 100%CPU when browser is on

[Test Rat]

Yuri <yuri at rawbw.com> writes:

> I saw this with firefox, now I see the same with chrome.
>
> After a while when the browser is launched with ~10 tabs open, Xorg
> begins to consume 100% CPU and all graphics apps get
> sluggish. Quitting the browser brings situation back to normal.
[...]

Have you tried to reproduce with a more simple test case after looking
at what sorts of requests firefox/chrome sends to Xserver via xscope/xmon?
You can also trace what it's doing with pmcstat/dtrace.

I don't see your issue, only rarely the one in ports/156889.