Log a message when a key frame packet is received

R=stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/1518004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@4089 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/video_coding/main/source/receiver.cc

@@ -77,6 +77,11 @@ void VCMReceiver::UpdateRtt(uint32_t rtt) {
 int32_t VCMReceiver::InsertPacket(const VCMPacket& packet,
                                   uint16_t frame_width,
                                   uint16_t frame_height) {
+  WEBRTC_TRACE(webrtc::kTraceInfo, webrtc::kTraceVideoCoding,
+               VCMId(vcm_id_, receiver_id_),
+               "Inserting key frame packet seqnum=%u, timestamp=%u",
+               packet.seqNum, packet.timestamp);
+
   // Insert the packet into the jitter buffer. The packet can either be empty or
   // contain media at this point.
   bool retransmitted = false;