No longer compatible with current Chromecast receiver library.

Not sure if anyone else has run into this, but the more recent chromecast receiver lib versions make use of `window.crypto` - which is not fully supported or polyfilled in the LG client environment.

Here is the polyfill I am currently using as a workaround:
https://gist.github.com/jozecuervo/f7d83d75654f37ed7e96

Thanks,
