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/packet_buffer.h b/modules/video_coding/packet_buffer.h
index f4dbe31..51528a6 100644
--- a/modules/video_coding/packet_buffer.h
+++ b/modules/video_coding/packet_buffer.h
@@ -71,7 +71,7 @@
     bool buffer_cleared = false;
   };
 
-  // Both |start_buffer_size| and |max_buffer_size| must be a power of 2.
+  // Both `start_buffer_size` and `max_buffer_size` must be a power of 2.
   PacketBuffer(size_t start_buffer_size, size_t max_buffer_size);
   ~PacketBuffer();
 
@@ -107,7 +107,7 @@
   // If the packet buffer has received its first packet.
   bool first_packet_received_;
 
-  // If the buffer is cleared to |first_seq_num_|.
+  // If the buffer is cleared to `first_seq_num_`.
   bool is_cleared_to_first_seq_num_;
 
   // Buffer that holds the the inserted packets and information needed to