Port ANS from aom/master 25aaf40

Reconciles the following commits from aom/master to nextgenv2:
- 25aaf40bbc24beeb52de9af7d7624b7d7c6ce9de
- 87073de5693df70eba1c9b9be2b2732ed3b08fb3

Change-Id: Ideda50a6ec75485cb4fa7437c69f4e58d6a2ca73
12 files changed