Bug 1839451 - Vendor libwebrtc from bff2e27076

Upstream commit: https://webrtc.googlesource.com/src/+/bff2e27076c6dd28e28f929a09d03ef8e424b8dc
    Deflake RTCStatsIntegrationTest::GetStatsFromCallee

    The test may sometimes fail because the round trip time has not been
    estimated. Wait until the report contains the round trip time before
    proceeding, or fail after 10 s.

    Fixed: webrtc:14952
    Change-Id: I9127b8ee6afa7454d061de96f002422d7d4af428
    Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/295724
    Commit-Queue: Johannes Kron <kron@webrtc.org>
    Reviewed-by: Henrik Boström <hbos@webrtc.org>
    Cr-Commit-Position: refs/heads/main@{#39438}

third_party/libwebrtc/README.moz-ff-commit

@@ -21951,3 +21951,6 @@ c0f8813870
 # MOZ_LIBWEBRTC_SRC=/Users/jan-ivar/moz/elm/.moz-fast-forward/moz-libwebrtc MOZ_LIBWEBRTC_BRANCH=mozpatches bash dom/media/webrtc/third_party_build/fast-forward-libwebrtc.sh
 # base of lastest vendoring
 cec9d00769
+# MOZ_LIBWEBRTC_SRC=/Users/jan-ivar/moz/elm/.moz-fast-forward/moz-libwebrtc MOZ_LIBWEBRTC_BRANCH=mozpatches bash dom/media/webrtc/third_party_build/fast-forward-libwebrtc.sh
+# base of lastest vendoring
+bff2e27076

third_party/libwebrtc/README.mozilla

@@ -14656,3 +14656,5 @@ libwebrtc updated from /Users/jan-ivar/moz/elm/.moz-fast-forward/moz-libwebrtc c
 libwebrtc updated from /Users/jan-ivar/moz/elm/.moz-fast-forward/moz-libwebrtc commit mozpatches on 2023-06-29T15:26:46.052111.
 # ./mach python dom/media/webrtc/third_party_build/vendor-libwebrtc.py --from-local /Users/jan-ivar/moz/elm/.moz-fast-forward/moz-libwebrtc --commit mozpatches libwebrtc
 libwebrtc updated from /Users/jan-ivar/moz/elm/.moz-fast-forward/moz-libwebrtc commit mozpatches on 2023-06-29T15:28:04.852935.
+# ./mach python dom/media/webrtc/third_party_build/vendor-libwebrtc.py --from-local /Users/jan-ivar/moz/elm/.moz-fast-forward/moz-libwebrtc --commit mozpatches libwebrtc
+libwebrtc updated from /Users/jan-ivar/moz/elm/.moz-fast-forward/moz-libwebrtc commit mozpatches on 2023-06-29T15:29:29.135396.

third_party/libwebrtc/pc/rtc_stats_integrationtest.cc

@@ -1165,7 +1165,17 @@ TEST_F(RTCStatsIntegrationTest, GetStatsFromCaller) {
 TEST_F(RTCStatsIntegrationTest, GetStatsFromCallee) {
   StartCall();
 
-  rtc::scoped_refptr<const RTCStatsReport> report = GetStatsFromCallee();
+  rtc::scoped_refptr<const RTCStatsReport> report;
+  // Wait for round trip time measurements to be defined.
+  constexpr int kMaxWaitMs = 10000;
+  auto GetStatsReportAndReturnTrueIfRttIsDefined = [&report, this] {
+    report = GetStatsFromCallee();
+    auto inbound_stats =
+        report->GetStatsOfType<RTCRemoteInboundRtpStreamStats>();
+    return !inbound_stats.empty() &&
+           inbound_stats.front()->round_trip_time_measurements.is_defined();
+  };
+  EXPECT_TRUE_WAIT(GetStatsReportAndReturnTrueIfRttIsDefined(), kMaxWaitMs);
   RTCStatsReportVerifier(report.get()).VerifyReport({});
 
 #if RTC_TRACE_EVENTS_ENABLED