Remove RTCRemoteInboundRtpStreamStats duplicate members.

The RTCReceivedRtpStreamStats hierarchy, which inherit from
RTCRtpStreamStats, already contain members ssrc, kind, codec_id and
transport_id so there's no need to list them inside
RTCRemoteInboundrtpStreamStats.

This CL removes duplicates so that we don't DCHECK-crash on Android,
and adds a unit test ensuring we never accidentally list the same
member twice.

Bug: webrtc:12658
Change-Id: I27925eadddc6224bf6d6a91784ed7cafd7a4cfb3
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/214343
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33649}

pc/rtc_stats_integrationtest.cc

@@ -1285,6 +1285,20 @@ TEST_F(RTCStatsIntegrationTest, GetStatsReferencedIds) {
     }
   }
 }
+
+TEST_F(RTCStatsIntegrationTest, GetStatsContainsNoDuplicateMembers) {
+  StartCall();
+
+  rtc::scoped_refptr<const RTCStatsReport> report = GetStatsFromCallee();
+  for (const RTCStats& stats : *report) {
+    std::set<std::string> member_names;
+    for (const auto* member : stats.Members()) {
+      EXPECT_TRUE(member_names.find(member->name()) == member_names.end())
+          << member->name() << " is a duplicate!";
+      member_names.insert(member->name());
+    }
+  }
+}
 #endif  // WEBRTC_HAVE_SCTP
 
 }  // namespace

stats/rtcstats_objects.cc

@@ -894,10 +894,6 @@ RTCOutboundRTPStreamStats::~RTCOutboundRTPStreamStats() {}
 WEBRTC_RTCSTATS_IMPL(
     RTCRemoteInboundRtpStreamStats, RTCReceivedRtpStreamStats,
         "remote-inbound-rtp",
-    &ssrc,
-    &kind,
-    &transport_id,
-    &codec_id,
     &local_id,
     &round_trip_time,
     &fraction_lost,