Potential division by zero in RtpToNtpMs()

webrtc/system_wrappers/source/rtp_to_ntp.cc

Index: webrtc/system_wrappers/source/rtp_to_ntp.cc
diff --git a/webrtc/system_wrappers/source/rtp_to_ntp.cc b/webrtc/system_wrappers/source/rtp_to_ntp.cc
index 706d861b55c82b0457516131c87b2412e87c16ca..6504737fd54bb32d84125bba2f8e4159a7005006 100644
--- a/webrtc/system_wrappers/source/rtp_to_ntp.cc
+++ b/webrtc/system_wrappers/source/rtp_to_ntp.cc
@@ -71,8 +71,9 @@ bool UpdateRtcpList(uint32_t ntp_secs,
 
   for (RtcpList::iterator it = rtcp_list->begin();
        it != rtcp_list->end(); ++it) {
-    if (measurement.ntp_secs == (*it).ntp_secs &&
-        measurement.ntp_frac == (*it).ntp_frac) {
+    if ((measurement.ntp_secs == (*it).ntp_secs &&
+         measurement.ntp_frac == (*it).ntp_frac) ||
+        (measurement.rtp_timestamp == (*it).rtp_timestamp)) {
       // This RTCP has already been added to the list.
       return true;
     }