[e] (0) Try to explain why postMessage()'s privacy implications aren't actually anything new
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=26305
Affected topics: DOM APIs, HTML

git-svn-id: http://svn.whatwg.org/webapps@8741 340c8d12-0b0e-0410-8428-c7bf67bfef74
Merge remote branch 'origin/master' into whatwg