Add RTCOutboundRTPStreamStats and all of its members.
https://w3c.github.io/webrtc-stats/#outboundrtpstats-dict*
dictionary RTCOutboundRTPStreamStats : RTCRTPStreamStats {
unsigned long packetsSent;
unsigned long long bytesSent;
double targetBitrate;
double roundTripTime;
unsigned long framesEncoded; // Since 14 December 2016 Draft
};
Comment 1 by bugdroid1@chromium.org
, Oct 31 2016