McAdoo has never been a head coach before, but he has been an assistant at the NFL level since 2004. He spent this season as a quarterbacks coach in Green Bay after spending the previous six as a tight ends coach. McAdoo's entire NFL career has been on the offensive side of the ball, just like previous head coach Rob Chudzinski.
The Browns fired Chudzinski after one season, going 4-12 including losing his final seven games of the year. There have been rumors that Cleveland would like to hit the college ranks, but none of that has been confirmed.
Regardless of who the Browns hire, the next coach will be their seventh since coming back into existence in 1999, not including interim coaches.