Revert "Remove VideoSendStreamInput::PutFrame."

This reverts r6229.

Test WebRtcVideoChannel2BaseTest.MuteStream fails after r6229.

BUG=
R=stefan@webrtc.org
TBR=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/19529005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6230 4adac7df-926f-26a2-2b94-8c16560cd09d