Can't register a serviceWorker

I'd like to be able to register a service worker:
navigator.serviceWorker.register('/sw.js');

Access to service workers is denied in this document origin.

Is looks like there is a function that can be called to override this, but I'm not sure where it needs to be called from:
registerURLSchemeAsAllowingServiceWorkers("file");

According to this issue, this should be enabled by default from Electron v0.36.0:
https://github.com/electron/electron/issues/2831

Is there any way to get this working with the current bits?