Remove VideoRotationMode to VideoRotation.

With this change, there is only one copy of rotation enum.

BUG=4145
R=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/48369004

Cr-Original-Commit-Position: refs/heads/master@{#8654}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 59140d6a5aaabb95beaad20d63f38d8755642940
19 files changed