It causes onpaste-text-html-types.html to fail.
Committed r80531: <http://trac.webkit.org/changeset/80531>
Err, I forgot webkit-patch does that thing.
Landed - https://github.com/WebKit/WebKit/commit/853d78b4d4c0b74cd45896a210d00802176da810
<rdar://problem/103466956>