Antitrust isn't about committing a crime so much as competing so well that the the company sucks the oxygen from the room. Becoming a monopoly isn't evil. It's an excess of success.

It's the responsibility of government antitrust law, not Google, to 'un-distort' the playing field and resurrect competition / opportunity. No one expects a corporation to voluntarily give away marketshare to ensure it doesn't run afoul of antitrust law, just because the company also vowed not to be evil. A negotiated settlement with regulators is exactly where this kind of matter should lead; no crime done.