Two sections for the actual CodeLabs site source are flagged deprecated and marked for for removal in Feb 2020

[the-nose-knows]

Platform: MacBook/Intel
OS: Mojave 10.14.6
Browser: Chrome "Version 76.0.3809.100 (Official Build) (64-bit)"

Steps to Reproduce:

1. Open the Chrome browser's console with command+option+J
2. Go to the CodeLab from that Chrome browser: https://codelabs.developers.google.com/codelabs/webrtc-web
3. Observe the console

Result:
Two warnings appear.

1. [Deprecation] HTML Imports is deprecated and will be removed in M80, around February 2020. Please use ES modules instead. See https://www.chromestatus.com/features/5144752345317376 and https://developers.google.com/web/updates/2019/07/web-components-time-to-upgrade for more details.

2. [Deprecation] document.registerElement is deprecated and will be removed in M80, around February 2020. Please use window.customElements.define instead. See https://www.chromestatus.com/features/4642138092470272 and https://developers.google.com/web/updates/2019/07/web-components-time-to-upgrade for more details.