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

Bug: webrtc:12338
Change-Id: Ib97b2c3d64dbd895f261ffa76a2e885bd934a87f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/226940
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34554}
diff --git a/api/video_codecs/video_encoder_config.h b/api/video_codecs/video_encoder_config.h
index 5916374..5440f1f 100644
--- a/api/video_codecs/video_encoder_config.h
+++ b/api/video_codecs/video_encoder_config.h
@@ -24,7 +24,7 @@
 
 namespace webrtc {
 
-// The |VideoStream| struct describes a simulcast layer, or "stream".
+// The `VideoStream` struct describes a simulcast layer, or "stream".
 struct VideoStream {
   VideoStream();
   ~VideoStream();
@@ -46,7 +46,7 @@
   int max_bitrate_bps;
 
   // Scaling factor applied to the stream size.
-  // |width| and |height| values are already scaled down.
+  // `width` and `height` values are already scaled down.
   double scale_resolution_down_by;
 
   // Maximum Quantization Parameter to use when encoding the stream.
@@ -171,7 +171,7 @@
   // The simulcast layer's configurations set by the application for this video
   // sender. These are modified by the video_stream_factory before being passed
   // down to lower layers for the video encoding.
-  // |simulcast_layers| is also used for configuring non-simulcast (when there
+  // `simulcast_layers` is also used for configuring non-simulcast (when there
   // is a single VideoStream).
   std::vector<VideoStream> simulcast_layers;