I personally believe (without any evidence) that they are ambivalent, maybe slightly opposed. However, they needed to oppose in public, otherwise, this would have been a PR disaster:
Publishers: "You steal our content and are unwilling to pay, so we need a law!"
Google: "You're right, please do the law, because it would harm our competitors!"
Publishers: "You steal our content and are unwilling to pay, so we need a law!"
Google: "You're right, please do the law, because it would harm our competitors!"