RTCInboundRTPStreamStats.packetsLost set by RTCStatsCollector.

Spec: https://w3c.github.io/webrtc-stats/#dom-rtcinboundrtpstreamstats-packetslost

BUG=chromium:657855

Review-Url: https://codereview.webrtc.org/2559973002
Cr-Commit-Position: refs/heads/master@{#15507}
diff --git a/webrtc/api/rtcstatscollector.cc b/webrtc/api/rtcstatscollector.cc
index 9f08aa9..a7c4cfc 100644
--- a/webrtc/api/rtcstatscollector.cc
+++ b/webrtc/api/rtcstatscollector.cc
@@ -150,6 +150,8 @@
       static_cast<uint32_t>(media_receiver_info.packets_rcvd);
   inbound_stats->bytes_received =
       static_cast<uint64_t>(media_receiver_info.bytes_rcvd);
+  inbound_stats->packets_lost =
+      static_cast<uint32_t>(media_receiver_info.packets_lost);
   inbound_stats->fraction_lost =
       static_cast<double>(media_receiver_info.fraction_lost);
 }