MS: Okay, gooogle, you win, we aren't good at making browsers like you are. Can you take on all the responsibility of making this browser work while we focus solely on what our customers want?
So they can basically blame Google for everything while spending all their time building on top of chrome.
For these reasons Microsoft did not win the browser war, because there is no war if there isn't anything financially important to fight over.
on edit: changed a was to were.
PS: That's what most of these companies do.