commit 02d2a92d92d05c3014d779efd5c03e0822b7dbe7
author hbos <hbos@webrtc.org> Wed Dec 21 09:29:05 2016
committer Commit bot <commit-bot@chromium.org> Wed Dec 21 09:29:05 2016
tree 055da71b07896819403f4e0515c8b54db322d776
parent 2a495ca2971282bda060d603e95a498dd9839689

RTCStatsReport::AddStats DCHECKs that the ID is unique.

Previously it was allowed to call AddStats with stats of the same ID
multiple times.

This revealed a few things:
- Local and remote streams can have the same label.
  RTCMediaStreamStats's ID is updated to include "local"/"remote".
- The same certificate can show up multiple times (e.g. for local and
  remote in a loopback), so we skip creating RTCCertificateStats for the
  same certificate multiple times

BUG=chromium:627816

Review-Url: https://codereview.webrtc.org/2593503003
Cr-Commit-Position: refs/heads/master@{#15730}

webrtc/api/rtcstatscollector.cc

diff --git a/webrtc/api/rtcstatscollector.cc b/webrtc/api/rtcstatscollector.cc
index f1c7ed7..cf97057 100644
--- a/webrtc/api/rtcstatscollector.cc
+++ b/webrtc/api/rtcstatscollector.cc
@@ -233,8 +233,17 @@
   RTCCertificateStats* prev_certificate_stats = nullptr;
   for (const rtc::SSLCertificateStats* s = &certificate_stats; s;
        s = s->issuer.get()) {
+    std::string certificate_stats_id =
+        RTCCertificateIDFromFingerprint(s->fingerprint);
+    // It is possible for the same certificate to show up multiple times, e.g.
+    // if local and remote side use the same certificate in a loopback call.
+    // If the report already contains stats for this certificate, skip it.
+    if (report->Get(certificate_stats_id)) {
+      RTC_DCHECK_EQ(s, &certificate_stats);
+      break;
+    }
     RTCCertificateStats* certificate_stats = new RTCCertificateStats(
-        RTCCertificateIDFromFingerprint(s->fingerprint), timestamp_us);
+        certificate_stats_id, timestamp_us);
     certificate_stats->fingerprint = s->fingerprint;
     certificate_stats->fingerprint_algorithm = s->fingerprint_algorithm;
     certificate_stats->base64_certificate = s->base64_certificate;
@@ -288,8 +297,9 @@
     MediaStreamInterface* stream = streams->at(i);
 
     std::unique_ptr<RTCMediaStreamStats> stream_stats(
-        new RTCMediaStreamStats("RTCMediaStream_" + stream->label(),
-                                timestamp_us));
+        new RTCMediaStreamStats(
+            (is_local ? "RTCMediaStream_local_" : "RTCMediaStream_remote_") +
+            stream->label(), timestamp_us));
     stream_stats->stream_identifier = stream->label();
     stream_stats->track_ids = std::vector<std::string>();
     // Audio Tracks