currently for the given accessible we get frame at point, run by parents to get direct child and repeat this for the obtained direct child.

Can you describe the changes in the patch and what it improves? Thanks

Hakan, for APIs that just need to get to the deepest descendant at a point, it's faster now because it removes a loop. The internal API can now give you the descendant directly. The old GetChildAtPoint() is still available and uses the logic in the new method that returns the deepest child at that point.

Comment on attachment 338787 [details] [diff] [review] patch Sounds good to me. r=me on the mac part if Aaron is happy with the xp a11y changes

checked in http://hg.mozilla.org/mozilla-central/rev/a7c78d54ebbd