[webkit-dev] Detecting a finished paint via JavaScript

[RDC]

> Would you be willing elaborate on why you want this?

Of course; I would like it for benchmarking page rendering 
times--something I believe would be possible with Web Inspector, but I'm 
after a cross-browser way of achieving it.

At the moment I have a benchmark that uses the onLoad event to move onto 
the next page; on Firefox this sometimes results in pages being 
"skipped" as the onLoad event is triggered before any painting is done. 
We use the mozAfterPaint to control this somewhat (though not completely 
effectively--any DOM manipulation via JS causes further paint events, 
but by this time the onLoad has fired).

Thinking more about it, perhaps it is the case that WebKit doesn't 
behave in exactly the same way, and the afterPaint event is not needed 
to guarantee that at least *some* of the page is painted before moving on.

-R