[agiow] (0) New BroadcastChannel feature to send messages to other tabs in the same origin, so you don't have to abuse the onstorage event, and don't need to use a heavy shared worker for something otherwise trivial.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=22628
Affected topics: DOM APIs, HTML

git-svn-id: http://svn.whatwg.org/webapps@8274 340c8d12-0b0e-0410-8428-c7bf67bfef74