[giow] (2) Match reality. It's a bit more useful anyway, arguably.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=17195
Affected topics: Microdata

git-svn-id: http://svn.whatwg.org/webapps@7705 340c8d12-0b0e-0410-8428-c7bf67bfef74