Mozilla currently has no search product. However, they do have a browser. Google also has a browser. Destroying Google search would destroy Google revenue, which would degrade browser quality. Long term, Mozilla should be interested in destroying Google search.

I can't imagine that declining revenues would hurt Chrome. There are lots of other ways for Google to cut costs before limiting their investment in the browser.

And Mozilla has always been happy to ride the coat tails of Google Search. Declining AdWords revenue just means declining Mozilla revenue. Even if the two aren't partnering together going forward, Google helped Mozilla negotiate a high bid with Yahoo.

Long term, I think Mozilla wants to see Firefox OS compete with Android. There's a lot more revenue potential there and the best chance to rapidly grow their user base.

But Mozilla is itself mostly funded by Search Engines. Who pay to be included or set as the default engine.