Add tracing to upper-level WebRTC calls.

talk/media/webrtc/webrtcvideoengine2.cc

 /*
  * libjingle
  * Copyright 2014 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 770 matching lines @@
     before[i].codec.preference = 0;
     after[i].codec.preference = 0;
     if (before[i] != after[i]) {
       return true;
     }
   }
   return false;
 }
 
 bool WebRtcVideoChannel2::SetSendParameters(const VideoSendParameters& params) {
+  TRACE_EVENT0("webrtc", "WebRtcVideoChannel2::SetSendParameters");
   LOG(LS_INFO) << "SetSendParameters: " << params.ToString();
   // TODO(pbos): Refactor this to only recreate the send streams once
   // instead of 4 times.
   return (SetSendCodecs(params.codecs) &&
           SetSendRtpHeaderExtensions(params.extensions) &&
           SetMaxSendBandwidth(params.max_bandwidth_bps) &&
           SetOptions(params.options));
 }
 
 bool WebRtcVideoChannel2::SetRecvParameters(const VideoRecvParameters& params) {
+  TRACE_EVENT0("webrtc", "WebRtcVideoChannel2::SetRecvParameters");
   LOG(LS_INFO) << "SetRecvParameters: " << params.ToString();
   // TODO(pbos): Refactor this to only recreate the recv streams once
   // instead of twice.
   return (SetRecvCodecs(params.codecs) &&
           SetRecvRtpHeaderExtensions(params.extensions));
 }
 
 std::string WebRtcVideoChannel2::CodecSettingsVectorToString(
     const std::vector<VideoCodecSettings>& codecs) {
   std::stringstream out;
@@ skipping 1872 matching lines @@
       video_codecs[i].rtx_payload_type = rtx_mapping[video_codecs[i].codec.id];
     }
   }
 
   return video_codecs;
 }
 
 }  // namespace cricket
 
 #endif  // HAVE_WEBRTC_VIDEO