The driving force behind this feature do seem to be a couple of Googlers, but at least one person from Mozilla and one from Apple have been involved in the discussion and contributed to the spec changes.
The changes have not been accepted into the spec, however, or even reviewed by W3C-TAG, so it isn't a standard yet.
The Mozilla person involved in that discussion is the editor of the relevant spec, and is only involved in terms of making sure the changes are correctly indicated in the spec. I don't believe he has expressed any opinion on the changes themselves.
You can find the full discussion here: https://github.com/whatwg/html/pull/3752