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/rtcstats_integrationtest.cc b/webrtc/api/rtcstats_integrationtest.cc
index 6648eb2..4c57304 100644
--- a/webrtc/api/rtcstats_integrationtest.cc
+++ b/webrtc/api/rtcstats_integrationtest.cc
@@ -469,7 +469,7 @@
     VerifyRTCRTPStreamStats(inbound_stream, &verifier);
     verifier.TestMemberIsDefined(inbound_stream.packets_received);
     verifier.TestMemberIsDefined(inbound_stream.bytes_received);
-    verifier.TestMemberIsUndefined(inbound_stream.packets_lost);
+    verifier.TestMemberIsDefined(inbound_stream.packets_lost);
     if (inbound_stream.media_type.is_defined() &&
         *inbound_stream.media_type == "video") {
       verifier.TestMemberIsUndefined(inbound_stream.jitter);