Implement googContentType GetStats metric reported on receive side.

webrtc/media/engine/webrtcvideoengine.cc

Index: webrtc/media/engine/webrtcvideoengine.cc
diff --git a/webrtc/media/engine/webrtcvideoengine.cc b/webrtc/media/engine/webrtcvideoengine.cc
index cd34e6b478786b11010e84197f4fd9214d15dbd1..b190df414d001edc29e1c929fafb3ef90b333a17 100644
--- a/webrtc/media/engine/webrtcvideoengine.cc
+++ b/webrtc/media/engine/webrtcvideoengine.cc
@@ -2428,6 +2428,8 @@ WebRtcVideoChannel::WebRtcVideoReceiveStream::GetVideoReceiverInfo(
 
   info.interframe_delay_max_ms = stats.interframe_delay_max_ms;
 
+  info.content_type = stats.content_type;
+
   info.codec_name = GetCodecNameFromPayloadType(stats.current_payload_type);
 
   info.firs_sent = stats.rtcp_packet_type_counts.fir_packets;