[VuWall-Matt]

Would this mean that you can encode the Chrome windows itself and send it off over the network to be decoded by, well, anything that decodes H.264, possibly another Chrome window's decoder?

[jallmann]

Yes, with the mediaSource constraint you can do screen sharing in WebRTC, but that's not anything specific to H.264.

[Excavator]

For a demo of screen, window, and application sharing see:

https://mozilla.github.io/webrtc-landing/gum_test.html