I don't think so, but close. I think they're indirectly paid by Google to keep Firefox around as a token competitor for antitrust purposes. I'm sure that's what the "search deal" is really about. Because Google already owns the search market, they don't have to pay for it.
However with falling marketshare there comes a point that when that won't fool regulators anymore. And then there's no point for Google to keep paying.
The C-level execs getting their salaries off that Google money can!