Google haven't really had much input into the chip, which is essentially a version of a Samsung Exynos. It's all standard off the shelf chips, all Google have done is a bit of a pic and mix that is all, then had it rebranded. Honestly I wouldn't be surprised if a teardown of the phone, and if they can see the chip (it might have memory stacked on top) that it just doesn't say "Samsung Exynos" with some part number. Even the source code apparently has references to Samsung Exynos.
It is basically a Samsung designed SoC and Samsung designed phone. I can see the meetings between Samsung and Google with Google picking things and Samsung engineers just rolling their eyes saying "that doesn't make sense and you can't do that" and Google leaving in a mood for not getting what they wanted