Yeah but is this entirely true though? It seems Google pays FF just for existing, to protect them from antitrust litigation (or what's left of it); so Google can't really stop paying FF and can't try to kill it, as its death would be extremely counter productive. FF may be freer than it thinks.
Its not impossible that someday a new non-chromium browser reaches feature parity (or close enough) with the chromium browsers. At that point, Google could stop worrying about funding Firefox's development.
Same as for Apple, the amount Google pays will vary. Firefox will probably still exist with 10% of Google's money, except execs Mozilla execs would be in a very different situation.