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You were probably thinking of Google Desktop which could search almost anything on your machine.

I went looking and it was indeed Chrome that could do it. See screenshot from 2009 here: https://superuser.com/a/42499

Apparently Opera supported it too at the time, and from the comments Safari as well.

Performance reasons seem to have killed it. I'd think that after 10 years now any modern computer would be able to handle it.

That's an interesting find.