Some cleanup in BaseChannel RTCP mux code.

webrtc/pc/rtcpmuxfilter.cc

Index: webrtc/pc/rtcpmuxfilter.cc
diff --git a/webrtc/pc/rtcpmuxfilter.cc b/webrtc/pc/rtcpmuxfilter.cc
index 86d4b6cd074f7b920fe4b429893ae7097f636df5..715e1e77984ac2fa2b3c1cee280578e2ecce1410 100644
--- a/webrtc/pc/rtcpmuxfilter.cc
+++ b/webrtc/pc/rtcpmuxfilter.cc
@@ -17,10 +17,16 @@ namespace cricket {
 RtcpMuxFilter::RtcpMuxFilter() : state_(ST_INIT), offer_enable_(false) {
 }
 
+bool RtcpMuxFilter::IsFullyActive() const {
+  return state_ == ST_ACTIVE;
+}
+
+bool RtcpMuxFilter::IsProvisionallyActive() const {
+  return state_ == ST_SENTPRANSWER || state_ == ST_RECEIVEDPRANSWER;
+}
+
 bool RtcpMuxFilter::IsActive() const {
-  return state_ == ST_SENTPRANSWER ||
-         state_ == ST_RECEIVEDPRANSWER ||
-         state_ == ST_ACTIVE;
+  return IsFullyActive() || IsProvisionallyActive();
 }
 
 void RtcpMuxFilter::SetActive() {