Implement googContentType GetStats metric reported on receive side.

webrtc/pc/statscollector.cc

 /*
  *  Copyright 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 252 matching lines @@
     report->AddInt(i.name, i.value);
   report->AddString(StatsReport::kStatsValueNameMediaType, "video");
 
   if (info.timing_frame_info) {
     report->AddString(StatsReport::kStatsValueNameTimingFrameInfo,
                       info.timing_frame_info->ToString());
   }
 
   report->AddInt64(StatsReport::kStatsValueNameInterframeDelayMaxMs,
                    info.interframe_delay_max_ms);
+
+  report->AddString(
+      StatsReport::kStatsValueNameContentType,
+      webrtc::videocontenttypehelpers::ToString(info.content_type));

[tommi, 2017/09/04 09:27:42]

since AddString supports static literals, can we change ToString() to not create
copies of the literals but instead just return const char*?

[ilnik, 2017/09/04 09:41:07]

Done.

 }
 
 void ExtractStats(const cricket::VideoSenderInfo& info, StatsReport* report) {
   ExtractCommonSendProperties(info, report);
 
   report->AddString(StatsReport::kStatsValueNameCodecImplementationName,
                     info.encoder_implementation_name);
   report->AddBoolean(StatsReport::kStatsValueNameBandwidthLimitedResolution,
                      (info.adapt_reason & 0x2) > 0);
   report->AddBoolean(StatsReport::kStatsValueNameCpuLimitedResolution,
@@ skipping 741 matching lines @@
     StatsReport* report = entry.second;
     report->set_timestamp(stats_gathering_started_);
   }
 }
 
 void StatsCollector::ClearUpdateStatsCacheForTest() {
   stats_gathering_started_ = 0;
 }
 
 }  // namespace webrtc