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/neteq/timestamp_scaler.h b/modules/audio_coding/neteq/timestamp_scaler.h
index 93cb953..4d578fc 100644
--- a/modules/audio_coding/neteq/timestamp_scaler.h
+++ b/modules/audio_coding/neteq/timestamp_scaler.h
@@ -37,15 +37,15 @@
   // Start over.
   virtual void Reset();
 
-  // Scale the timestamp in |packet| from external to internal.
+  // Scale the timestamp in `packet` from external to internal.
   virtual void ToInternal(Packet* packet);
 
-  // Scale the timestamp for all packets in |packet_list| from external to
+  // Scale the timestamp for all packets in `packet_list` from external to
   // internal.
   virtual void ToInternal(PacketList* packet_list);
 
-  // Returns the internal equivalent of |external_timestamp|, given the
-  // RTP payload type |rtp_payload_type|.
+  // Returns the internal equivalent of `external_timestamp`, given the
+  // RTP payload type `rtp_payload_type`.
   virtual uint32_t ToInternal(uint32_t external_timestamp,
                               uint8_t rtp_payload_type);