One test renderer per platform is sufficient, multiple code paths are bad. BUG= R=mflodman@webrtc.org Review URL: https://webrtc-codereview.appspot.com/1612004 git-svn-id: http://webrtc.googlecode.com/svn/trunk@4170 4adac7df-926f-26a2-2b94-8c16560cd09d