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

Bug: webrtc:12338
Change-Id: I72fcb505a92f03b2ace7160ee33d555a977eddfd
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/226955
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34587}
diff --git a/rtc_base/time_utils.cc b/rtc_base/time_utils.cc
index fe63d3a..96282f0 100644
--- a/rtc_base/time_utils.cc
+++ b/rtc_base/time_utils.cc
@@ -232,11 +232,11 @@
 
   // We will have added one day too much above if expiration is during a leap
   // year, and expiration is in January or February.
-  if (expiry_in_leap_year && month <= 2 - 1)  // |month| is zero based.
+  if (expiry_in_leap_year && month <= 2 - 1)  // `month` is zero based.
     day -= 1;
 
-  // Combine all variables into seconds from 1970-01-01 00:00 (except |month|
-  // which was accumulated into |day| above).
+  // Combine all variables into seconds from 1970-01-01 00:00 (except `month`
+  // which was accumulated into `day` above).
   return (((static_cast<int64_t>(year - 1970) * 365 + day) * 24 + hour) * 60 +
           min) *
              60 +