Improve threading annotations in `RenderingTracker`. Bug: b/423646186 Change-Id: Ibb174296f6f48460946f286af8da729634f50a84 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/481360 Auto-Submit: Rasmus Brandt <brandtr@webrtc.org> Commit-Queue: Åsa Persson <asapersson@webrtc.org> Reviewed-by: Åsa Persson <asapersson@webrtc.org> Cr-Commit-Position: refs/heads/main@{#48016}

diff --git a/video/timing/simulator/rendering_tracker.cc b/video/timing/simulator/rendering_tracker.cc
index 88fcbcd..b84a79c 100644
--- a/video/timing/simulator/rendering_tracker.cc
+++ b/video/timing/simulator/rendering_tracker.cc

@@ -173,12 +173,14 @@
 }
 
 void RenderingTracker::OnDroppedFrames(uint32_t frames_dropped) {
+  RTC_DCHECK_RUN_ON(&sequence_checker_);
   vsbc_frames_dropped_ = frames_dropped;
 }
 
 void RenderingTracker::OnDecodableFrame(TimeDelta jitter_buffer_delay,
                                         TimeDelta jitter_buffer_target_delay,
                                         TimeDelta jitter_buffer_minimum_delay) {
+  RTC_DCHECK_RUN_ON(&sequence_checker_);
   vsbc_decodable_stats_ = VideoStreamBufferControllerObserverDecodableStats{
       .jitter_buffer_delay = jitter_buffer_delay,
       .jitter_buffer_target_delay = jitter_buffer_target_delay,
@@ -200,6 +202,7 @@
 }
 
 void RenderingTracker::ResetVideoStreamBufferControllerObserverStats() {
+  RTC_DCHECK_RUN_ON(&sequence_checker_);
   vsbc_frames_dropped_.reset();
   vsbc_decodable_stats_.reset();
 }

diff --git a/video/timing/simulator/rendering_tracker.h b/video/timing/simulator/rendering_tracker.h
index 7acaf48..87d3dda 100644
--- a/video/timing/simulator/rendering_tracker.h
+++ b/video/timing/simulator/rendering_tracker.h

@@ -122,9 +122,9 @@
   // Stats state. This is needed since the stats and the decodable frame are
   // provided by the VSBC on different callbacks, but we want to log the
   // the corresponding information simultaneously to our callback.
-  std::optional<int> vsbc_frames_dropped_;
+  std::optional<int> vsbc_frames_dropped_ RTC_GUARDED_BY(sequence_checker_);
   std::optional<VideoStreamBufferControllerObserverDecodableStats>
-      vsbc_decodable_stats_;
+      vsbc_decodable_stats_ RTC_GUARDED_BY(sequence_checker_);
 
   // Outputs.
   RenderingTrackerEvents& observer_;