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

Bug: webrtc:12338
Change-Id: I02613d9fca45d00e2477f334b7a0416e7912e26b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227037
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34621}
diff --git a/modules/audio_coding/acm2/acm_receiver.h b/modules/audio_coding/acm2/acm_receiver.h
index 19dc577..9963603 100644
--- a/modules/audio_coding/acm2/acm_receiver.h
+++ b/modules/audio_coding/acm2/acm_receiver.h
@@ -177,9 +177,9 @@
   // enabled then the maximum NACK list size is modified accordingly.
   //
   // If the sequence number of last received packet is N, the sequence numbers
-  // of NACK list are in the range of [N - |max_nack_list_size|, N).
+  // of NACK list are in the range of [N - `max_nack_list_size`, N).
   //
-  // |max_nack_list_size| should be positive (none zero) and less than or
+  // `max_nack_list_size` should be positive (none zero) and less than or
   // equal to |Nack::kNackListSizeLimit|. Otherwise, No change is applied and -1
   // is returned. 0 is returned at success.
   //
@@ -189,12 +189,12 @@
   void DisableNack();
 
   //
-  // Get a list of packets to be retransmitted. |round_trip_time_ms| is an
+  // Get a list of packets to be retransmitted. `round_trip_time_ms` is an
   // estimate of the round-trip-time (in milliseconds). Missing packets which
   // will be playout in a shorter time than the round-trip-time (with respect
   // to the time this API is called) will not be included in the list.
   //
-  // Negative |round_trip_time_ms| results is an error message and empty list
+  // Negative `round_trip_time_ms` results is an error message and empty list
   // is returned.
   //
   std::vector<uint16_t> GetNackList(int64_t round_trip_time_ms) const;