Refactor some receive-side stats.

Removes polling of CName as well as receive codec statistics in favor of
internal callbacks keeping a statistics struct up to date.

R=mflodman@webrtc.org, stefan@webrtc.org
BUG=1667

Review URL: https://webrtc-codereview.appspot.com/28259005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7950 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/rtp_rtcp/source/rtcp_receiver.cc

@@ -809,6 +809,10 @@ void RTCPReceiver::HandleSDESChunk(RTCPUtility::RTCPParserV2& rtcpParser) {
 
   cnameInfo->name[RTCP_CNAME_SIZE - 1] = 0;
   strncpy(cnameInfo->name, rtcpPacket.CName.CName, RTCP_CNAME_SIZE - 1);
+  if (stats_callback_ != NULL) {
+    stats_callback_->CNameChanged(rtcpPacket.CName.CName,
+                                  rtcpPacket.CName.SenderSSRC);
+  }
 }
 
 // no need for critsect we have _criticalSectionRTCPReceiver