Add support for sharing GPU textures

The OBS Studio project currently implements their browser plugin using a fork of Chromium Embedded Framework (CEF) that adds support for sharing GPU textures for the on-screen renderer.

The original CEF PR for this: https://bitbucket.org/chromiumembedded/cef/pull-requests/285
The current updated fork with the PR code incorporated: https://github.com/obsproject/cef

Would it be possible to incorporate this capability into QtWebEngine? That would open the door for potentially a version of the OBS Browser plugin being written using QtWebEngine instead.