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/loss_notification_controller.h b/modules/video_coding/loss_notification_controller.h
index 4d536ba..ecba412 100644
--- a/modules/video_coding/loss_notification_controller.h
+++ b/modules/video_coding/loss_notification_controller.h
@@ -36,7 +36,7 @@
   ~LossNotificationController();
 
   // An RTP packet was received from the network.
-  // |frame| is non-null iff the packet is the first packet in the frame.
+  // `frame` is non-null iff the packet is the first packet in the frame.
   void OnReceivedPacket(uint16_t rtp_seq_num, const FrameDetails* frame);
 
   // A frame was assembled from packets previously received.
@@ -54,9 +54,9 @@
 
   // When the loss of a packet or the non-decodability of a frame is detected,
   // produces a key frame request or a loss notification.
-  // 1. |last_received_seq_num| is the last received sequence number.
-  // 2. |decodability_flag| refers to the frame associated with the last packet.
-  //    It is set to |true| if and only if all of that frame's dependencies are
+  // 1. `last_received_seq_num` is the last received sequence number.
+  // 2. `decodability_flag` refers to the frame associated with the last packet.
+  //    It is set to `true` if and only if all of that frame's dependencies are
   //    known to be decodable, and the frame itself is not yet known to be
   //    unassemblable (i.e. no earlier parts of it were lost).
   //    Clarifications:
@@ -90,7 +90,7 @@
   // the last decodable-and-non-discardable frame. Since this is a bit of
   // a mouthful, last_decodable_non_discardable_.first_seq_num is used,
   // which hopefully is a bit easier for human beings to parse
-  // than |first_seq_num_of_last_decodable_non_discardable_|.
+  // than `first_seq_num_of_last_decodable_non_discardable_`.
   struct FrameInfo {
     explicit FrameInfo(uint16_t first_seq_num) : first_seq_num(first_seq_num) {}
     uint16_t first_seq_num;