Have padding decay to zero if no frames are being captured.

BUG=1837
TEST=trybots
R=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2469004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4998 4adac7df-926f-26a2-2b94-8c16560cd09d
2 files changed