Adding Mac test renderer, some test refactoring and made cpplint pass.

BUG=1667
TEST=Rendered video in Mac loopback test.
R=pbos@webrtc.org, xians@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1554004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4112 4adac7df-926f-26a2-2b94-8c16560cd09d
14 files changed