It's important not to conflate "Google that develops a web browser" with "Google the advertising and search company". The same applies to the parts of Mozilla

It's important not to conflate "Google that develops a web browser" with "Google the advertising and search company". The same applies to the parts of Mozilla that would interact with these parts of Google. For both Google and Mozilla, the goals of these two (or more!) groups of decision makers will not necessarily align at all times. Ideally, whatever may be going on at the ad/search/business level shouldn't impact collaboration on web standards and implementation.