Initialize RTPVideoHeader fields to correctly set simulcastIdx for non VP8 codecs.

R=stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/39199004

Cr-Commit-Position: refs/heads/master@{#8421}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8421 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed