sending RTP module for the specified simulcast layer a frame belongs to. This CL also removes the corresponding functionality from the RTP RTCP module and fixes lint warnings in the files touched. BUG=769 TEST=New unittest and manual tests R=stefan@webrtc.org Review URL: https://webrtc-codereview.appspot.com/39629004 Cr-Commit-Position: refs/heads/master@{#8267} git-svn-id: http://webrtc.googlecode.com/svn/trunk@8267 4adac7df-926f-26a2-2b94-8c16560cd09d