The gc-9.html test shows that custom properties on some DOM objects are lost after GC.
Created attachment 34630 [details] patch
Comment on attachment 34630 [details] patch r=me
I'll leave this beauty for Darin to commit. If he'd rather have the script commit it for him, he can always set commit-queue+ himself. :)
http://trac.webkit.org/changeset/47165