Thanks for bringing this issue to our attention. Unfortunately Chromecast isn't Chromium(-OS) based, so there's little we can do about it on this tracker. I'll see if I can find a better place for the bug.

Interestingly, the links into Google Drive and Docs that are shown on that site are accessible without authentication.

Therefore, as a stop-gap measure, I paste them here for your convenience:

Chromecast Open Source Code: https://drive.google.com/a/google.com/folderview?id=0B3j4zj2IQp7MZkplRzRvcERtaU0

Chromecast Open Source Licenses: https://docs.google.com/document/d/1tj-qXqaZJO-Ivh19IOIMJWTrBeBSGTxRedYiQXbu0zY/pub

Google Cast for Android TV Open Source Code: https://drive.google.com/drive/folders/0B3j4zj2IQp7MaUgxa0dJclZWYms

Google Cast for Android TV Open Source Licenses: https://docs.google.com/document/u/1/d/1jnIrxXUL62c49WtTsC2F4gGOklnrTOcM-6lkzQOnrhc/pub

Google Cast audio devices Open Source Code: https://drive.google.com/corp/drive/u/0/folders/0B3j4zj2IQp7Mfi14T2dCZFFpZWVlOVM3cmNReEhndXVySFpJNUdWV1c0Yi1BYmFKOUtoNVU

Google Cast audio devices Open Source Licenses: https://docs.google.com/document/u/1/d/1FoGgmFHGpaUm6OaIOxhtuu1v0n9voqK3U-zvQxEZKBs/pub

Devices with Google Assistant Open Source Code: https://drive.google.com/corp/drive/folders/0B3j4zj2IQp7MNkRiVFNPd2VCajQ

Devices with Google Assistant Open Source Licenses: https://docs.google.com/document/d/1EzUPQ-xWlKwqGHhCdGNjhNqWk6CCYWxfMfnQT1E0WsA/edit

Oops, my mistake: the first link should be https://drive.google.com/drive/folders/0B3j4zj2IQp7MZkplRzRvcERtaU0, which works unauthenticated.