Suppressing warnings in GetRTT() in VoE.

GetRTT() was separated from GetRTPStatistics() but the warnings were not updated.

Now GetRTT() is only only used by GetRTPStatistics() and the warning pops up pointlessly and too often.

This CL is to suppress these warnings and maintain a proper warning for GetRTPStatistics().

BUG=
R=henrika@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/36469004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7899 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/voice_engine/channel.cc b/webrtc/voice_engine/channel.cc
index 91167c0..84b5cdf 100644
--- a/webrtc/voice_engine/channel.cc
+++ b/webrtc/voice_engine/channel.cc
@@ -3228,10 +3228,13 @@
 
     // --- RTT
     stats.rttMs = GetRTT();
-
-    WEBRTC_TRACE(kTraceStateInfo, kTraceVoice,
-                 VoEId(_instanceId, _channelId),
-                 "GetRTPStatistics() => rttMs=%d", stats.rttMs);
+    if (stats.rttMs == 0) {
+      WEBRTC_TRACE(kTraceWarning, kTraceVoice, VoEId(_instanceId, _channelId),
+                   "GetRTPStatistics() failed to get RTT");
+    } else {
+      WEBRTC_TRACE(kTraceStateInfo, kTraceVoice, VoEId(_instanceId, _channelId),
+                   "GetRTPStatistics() => rttMs=%d", stats.rttMs);
+    }
 
     // --- Data counters
 
@@ -4279,19 +4282,11 @@
 int Channel::GetRTT() const {
   RTCPMethod method = _rtpRtcpModule->RTCP();
   if (method == kRtcpOff) {
-    WEBRTC_TRACE(kTraceWarning, kTraceVoice,
-                 VoEId(_instanceId, _channelId),
-                 "GetRTPStatistics() RTCP is disabled => valid RTT "
-                 "measurements cannot be retrieved");
     return 0;
   }
   std::vector<RTCPReportBlock> report_blocks;
   _rtpRtcpModule->RemoteRTCPStat(&report_blocks);
   if (report_blocks.empty()) {
-    WEBRTC_TRACE(kTraceWarning, kTraceVoice,
-                 VoEId(_instanceId, _channelId),
-                 "GetRTPStatistics() failed to measure RTT since no "
-                 "RTCP packets have been received yet");
     return 0;
   }
 
@@ -4314,10 +4309,6 @@
   uint16_t min_rtt = 0;
   if (_rtpRtcpModule->RTT(remoteSSRC, &rtt, &avg_rtt, &min_rtt, &max_rtt)
       != 0) {
-    WEBRTC_TRACE(kTraceWarning, kTraceVoice,
-                 VoEId(_instanceId, _channelId),
-                 "GetRTPStatistics() failed to retrieve RTT from "
-                 "the RTP/RTCP module");
     return 0;
   }
   return static_cast<int>(rtt);