shaka-player: Chromecast crashes when using serviceWorkers?

Are serviceWorkers disabled on the chromecast, the app instantly crashed when called:

try {
    if ('serviceWorker' in navigator) {
        navigator.serviceWorker.getRegistrations().then(function(registrations) {
            for(let registration of registrations) {  
                registration.unregister();
                console.log('Unregister', registration)
            }
    	})
        navigator.serviceWorker.register('sw.js', {scope: './'}).then(function() {
          console.log('Success!')
        }).catch(function(err) {
            console.log(err);
        });
    } else {
        console.log('Service worker not supported')
    }
} catch (err) {
	console.log(err)
}