Use backticks not vertical bars to denote variables in comments

Bug: webrtc:12338
Change-Id: I89c8b3a328d04203177522cbdfd9e606fd4bce4c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/228246
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34696}
diff --git a/api/stats/rtcstats_objects.h b/api/stats/rtcstats_objects.h
index b18ef97..8a6327e 100644
--- a/api/stats/rtcstats_objects.h
+++ b/api/stats/rtcstats_objects.h
@@ -57,7 +57,7 @@
   static const char* const kFailed;
 };
 
-// |RTCMediaStreamTrackStats::kind| is not an enum in the spec but the only
+// `RTCMediaStreamTrackStats::kind` is not an enum in the spec but the only
 // valid values are "audio" and "video".
 // https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamtrackstats-kind
 struct RTCMediaStreamTrackKind {