Add more tracing for key frames.

R=mallinath@webrtc.org, stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1428004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4015 4adac7df-926f-26a2-2b94-8c16560cd09d
5 files changed