When running fast/css/getComputedStyle/computed-style.html test with --qt , although test passes, its result diffs from win and mac expected files in a few lines. Maybe a pixels precision, related to fonts or what ever...
see height, webkit-perspective-origin and webkit-transform-origin properties in http://pastebin.mozilla.org/659883
I am filing now as minor for future tracking.
if it is not something to worry about, few free to INVALID or WONTFIX it
ok, it's been fixed
also bot is already up.