[giow] (2) Make sandboxed iframes block document.domain setting
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=23040
Affected topics: HTML, Security

git-svn-id: http://svn.whatwg.org/webapps@8275 340c8d12-0b0e-0410-8428-c7bf67bfef74