message: VideoAdapter: add missing attribute thread annotations.
  Cr-Commit-Position: refs/heads/master@{#31311}
diff: @@ -99,12 +99,17 @@ class VideoAdapter {
  // Determine if frame should be dropped based on input fps and requested fps.
  bool KeepFrame(int64_t in_timestamp_ns);
  - int frames_in_; // Number of input frames.
  - int frames_out_; // Number of output frames.
  - int frames_scaled_; // Number of frames scaled.
  - int adaption_changes_; // Number of changes in scale factor.
  - int previous_width_; // Previous adapter output width.
  - int previous_height_; // Previous adapter output height.
  + int frames_in_ RTC_GUARDED_BY(critical_section_); // Number of input frames.
  + int frames_out_
  + RTC_GUARDED_BY(critical_section_); // Number of output frames.
  + int frames_scaled_
  + RTC_GUARDED_BY(critical_section_); // Number of frames scaled.
  + int adaption_changes_
  + RTC_GUARDED_BY(critical_section_); // Number of changes in scale factor.
  + int previous_width_
  + RTC_GUARDED_BY(critical_section_); // Previous adapter output width.
  + int previous_height_
  + RTC_GUARDED_BY(critical_section_); // Previous adapter output height.
  const bool variable_start_scale_factor_;
  // The fixed source resolution alignment requirement.
  