Nick Niemeir and Eric and Paul before him set up a test case signaling between pages with a BroadcastChannel. This was shown to not work between one frame plugin and another tab all its own. Here we work through another case trying to find someting that meets our needs. mdn 
Three versions tried, localStorage, sessionStorage, and BroadcastChannel.
pages/broadcast-channel
We try one more time to wrap count.html in an equivalent iFrame to see if they can connect. framed
http://ward.dojo.fed.wiki/assets/pages/broadcast-channel/count.html