It's present in my install of OpenSolaris 2008.11. I'm running Firefox 3.0.6 as downloaded from the mozilla.org ftp site:
http://releases.mozilla.org/pub/mozilla.org/firefox/releases/3.0.6/contrib/solaris_tarball/firefox-3.0.6.en-US.opensolaris-i386.tar.bz2 -- This message posted from opensolaris.org
