[giow] (3) Allow <select multiple> and <select size=4> to be used as canvas fallback
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=24749
Affected topics: Canvas

git-svn-id: http://svn.whatwg.org/webapps@8484 340c8d12-0b0e-0410-8428-c7bf67bfef74