Cleanup: unify rotation to be enum based instead of int for degree.
Cleanup: unify rotation to be enum based instead of int for degree.

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

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

Committed: https://code.google.com/p/webrtc/source/detail?r=8257

Review URL: https://webrtc-codereview.appspot.com/37129004

git-svn-id: 03ae4fbe531b1eefc9d815f31e49022782c42458@8276 4adac7df-926f-26a2-2b94-8c16560cd09d

Alkalyne/webrtctrunk,krieger-od/webrtc,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,aleonliao/webrtc-trunk,jchavanton/webrtc,Alkalyne/webrtctrunk,sippet/webrtc,krieger-od/webrtc,Alkalyne/webrtctrunk,aleonliao/webrtc-trunk,krieger-od/webrtc,jchavanton/webrtc,sippet/webrtc,aleonliao/webrtc-trunk,krieger-od/webrtc,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,sippet/webrtc,sippet/webrtc,aleonliao/webrtc-trunk,aleonliao/webrtc-trunk,sippet/webrtc,aleonliao/webrtc-trunk,jchavanton/webrtc,krieger-od/webrtc,krieger-od/webrtc,sippet/webrtc,jchavanton/webrtc,Alkalyne/webrtctrunk,jchavanton/webrtc,jchavanton/webrtc,jchavanton/webrtc