Fix AV sync issue

r4229 introduced an AV sync issue due to an error.
This is a one linear fix and provides the correct
current video delay for synchronization.

TBR=wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1675004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4231 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed