Implement minimum transmit bitrate.

Utilizing minimum transmission bitrate prevents low remote bitrate
estimates (bitrate estimation dips) when encoding non-complex content
such as screenshare of a static image even though there's nothing wrong
with the link.

Requires pacing to be enabled for now, pending issue 3036.

BUG=3014
R=mflodman@webrtc.org, stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/9719004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@5694 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/video_engine/vie_rtp_rtcp_impl.h b/video_engine/vie_rtp_rtcp_impl.h
index 227fa5e..3120bee 100644
--- a/video_engine/vie_rtp_rtcp_impl.h
+++ b/video_engine/vie_rtp_rtcp_impl.h
@@ -90,6 +90,8 @@
                                                int id);
   virtual int SetRtcpXrRrtrStatus(int video_channel, bool enable);
   virtual int SetTransmissionSmoothingStatus(int video_channel, bool enable);
+  virtual int SetMinTransmitBitrate(int video_channel,
+                                    int min_transmit_bitrate_kbps);
   virtual int GetReceiveChannelRtcpStatistics(const int video_channel,
                                               RtcpStatistics& basic_stats,
                                               int& rtt_ms) const;