"with the chrome javascript console" (sic) you can also add some javascript to your page (or use an extension like greasemonkey for custom scripting).
On your game add a script with a setInterval function that will call with your server every x seconds. And get the json encoded data of the configuration
On the other side, when validating your configuration, it will use Ajax to store information on your server (i.e. in a file)
To sum up :
In your parent windows, when you modify your configuration, an Ajax call is made to save the new config json encoded in a file on your server
In your child windows with the console (if no reload) or with a userscript extension (like GreaseMonkey) you add a setInterval javascript to load the array from the file on your server.
PS: This is theorical and not an invitation to cheat on a game you like.