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

Bug: webrtc:12338
Change-Id: Ia8a9adea291d594e4f59a6a1203a7bfb0758adac
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227165
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34684}
diff --git a/modules/video_coding/codec_timer.h b/modules/video_coding/codec_timer.h
index 412e4cc..2948b82 100644
--- a/modules/video_coding/codec_timer.h
+++ b/modules/video_coding/codec_timer.h
@@ -40,7 +40,7 @@
   int ignored_sample_count_;
   // Queue with history of latest decode time values.
   std::queue<Sample> history_;
-  // |filter_| contains the same values as |history_|, but in a data structure
+  // `filter_` contains the same values as `history_`, but in a data structure
   // that allows efficient retrieval of the percentile value.
   PercentileFilter<int64_t> filter_;
 };