Use backticks not vertical bars to denote variables in comments for /video

Bug: webrtc:12338
Change-Id: I47958800407482894ff6f17c1887dce907fdf35a
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227030
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34585}
diff --git a/video/stream_synchronization.h b/video/stream_synchronization.h
index 2da6a49..61073cb 100644
--- a/video/stream_synchronization.h
+++ b/video/stream_synchronization.h
@@ -33,15 +33,15 @@
                      int* total_audio_delay_target_ms,
                      int* total_video_delay_target_ms);
 
-  // On success |relative_delay_ms| contains the number of milliseconds later
+  // On success `relative_delay_ms` contains the number of milliseconds later
   // video is rendered relative audio. If audio is played back later than video
-  // |relative_delay_ms| will be negative.
+  // `relative_delay_ms` will be negative.
   static bool ComputeRelativeDelay(const Measurements& audio_measurement,
                                    const Measurements& video_measurement,
                                    int* relative_delay_ms);
 
   // Set target buffering delay. Audio and video will be delayed by at least
-  // |target_delay_ms|.
+  // `target_delay_ms`.
   void SetTargetBufferingDelay(int target_delay_ms);
 
   // Lowers the audio delay by 10%. Can be used to recover from errors.