I found a change in the experimental flag also on Windows where it still doesn't work. Maybe you have to enable it again?
Http://developers.google.com/web/updates/2015/07/interact-with-ble-devices-on-the-web
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I found a change in the experimental flag also on Windows where it still doesn't work. Maybe you have to enable it again?
Http://developers.google.com/web/updates/2015/07/interact-with-ble-devices-on-the-web