–INI–
HTML.SafeIframe = true
URI.SafeIframeRegexp = "%^http://www.youtube.com/embed/%"
–HTML–
<iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/r_enCwAbaGU" frameborder="0" allowfullscreen></iframe>
–EXPECT–
<iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/r_enCwAbaGU" frameborder="0"></iframe>
–# vim: et sw=4 sts=4