[giow] (1) A MessageEvent object constructed using MessageEventInit doesn't get the actual array that was passed, that would be weird. It gets a copy.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=23176
Affected topics: HTML

git-svn-id: http://svn.whatwg.org/webapps@8260 340c8d12-0b0e-0410-8428-c7bf67bfef74