add mediaType field to ssrc stat

talk/app/webrtc/statscollector.cc

Index: talk/app/webrtc/statscollector.cc
diff --git a/talk/app/webrtc/statscollector.cc b/talk/app/webrtc/statscollector.cc
index 7f5f925b8218a1b81af276b52188d27e6f2f1161..df9806dfe72f5e933fbf76a458e3c8518705f6b2 100644
--- a/talk/app/webrtc/statscollector.cc
+++ b/talk/app/webrtc/statscollector.cc
@@ -175,6 +175,7 @@ void ExtractStats(const cricket::VoiceReceiverInfo& info, StatsReport* report) {
                    info.bytes_rcvd);
   report->AddInt64(StatsReport::kStatsValueNameCaptureStartNtpTimeMs,
                    info.capture_start_ntp_time_ms);
+  report->AddString(StatsReport::kStatsValueNameMediaType, "audio");

[tommi, 2016/01/11 12:22:50]

Can you move this to the top of the function?

If you could also add a TODO for me:
// TODO(tommi): Look into setting the media type of a report when the report is
first created.

Same below.  The reason is that now we're setting this in several places while
it should be in only one place. Secondly we're setting it each time the report
is updated but this value should never change.

 }
 
 void ExtractStats(const cricket::VoiceSenderInfo& info, StatsReport* report) {
@@ -192,6 +193,7 @@ void ExtractStats(const cricket::VoiceSenderInfo& info, StatsReport* report) {
 
   for (const auto& i : ints)
     report->AddInt(i.name, i.value);
+  report->AddString(StatsReport::kStatsValueNameMediaType, "audio");
 }
 
 void ExtractStats(const cricket::VideoReceiverInfo& info, StatsReport* report) {
@@ -223,6 +225,7 @@ void ExtractStats(const cricket::VideoReceiverInfo& info, StatsReport* report) {
 
   for (const auto& i : ints)
     report->AddInt(i.name, i.value);
+  report->AddString(StatsReport::kStatsValueNameMediaType, "video");
 }
 
 void ExtractStats(const cricket::VideoSenderInfo& info, StatsReport* report) {
@@ -255,6 +258,7 @@ void ExtractStats(const cricket::VideoSenderInfo& info, StatsReport* report) {
 
   for (const auto& i : ints)
     report->AddInt(i.name, i.value);
+  report->AddString(StatsReport::kStatsValueNameMediaType, "video");
 }
 
 void ExtractStats(const cricket::BandwidthEstimationInfo& info,