CVO capturer feature: allow unrotated frame flows through the capture pipeline.

split from https://webrtc-codereview.appspot.com/37029004/

This is based on clean up code change at https://webrtc-codereview.appspot.com/37129004

BUG=4145
R=perkj@webrtc.org, pthatcher@webrtc.org, stefan@webrtc.org, tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/39799004

Cr-Commit-Position: refs/heads/master@{#8337}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8337 4adac7df-926f-26a2-2b94-8c16560cd09d
23 files changed