[racket] TR: (almost) no way to dismiss performance report window?

At Fri, 6 Jan 2012 12:24:40 -0800,
John Clements wrote:
> On my mac, the window summoned by a double-click after running
> Performance Report has no close box, and no close buttons, and no
> obvious way to dismiss it.  It turns out that choosing "Racket > Quit"
> from the menu gets rid of it, but on a Mac, this is *severely*
> unintuitive, as it appears that you're closing the whole
> application. Am I doing something silly?

I remember the same thing happening on Jay's machine (also a mac) at
RacketCon. On my machines (all Debian), I've never seen the problem.

This window is a `dialog%', which may be the problem. I'll change it
to a `frame%'.

Vincent