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/rtp_packet_info.h b/api/rtp_packet_info.h
index 605620d..13d3a39 100644
--- a/api/rtp_packet_info.h
+++ b/api/rtp_packet_info.h
@@ -23,9 +23,9 @@
 namespace webrtc {
 
 //
-// Structure to hold information about a received |RtpPacket|. It is primarily
+// Structure to hold information about a received `RtpPacket`. It is primarily
 // used to carry per-packet information from when a packet is received until
-// the information is passed to |SourceTracker|.
+// the information is passed to `SourceTracker`.
 //
 class RTC_EXPORT RtpPacketInfo {
  public:
@@ -102,8 +102,8 @@
 
   // Fields from the Absolute Capture Time header extension:
   // http://www.webrtc.org/experiments/rtp-hdrext/abs-capture-time
-  // To not be confused with |local_capture_clock_offset_|, the
-  // |estimated_capture_clock_offset| in |absolute_capture_time_| should
+  // To not be confused with `local_capture_clock_offset_`, the
+  // `estimated_capture_clock_offset` in `absolute_capture_time_` should
   // represent the clock offset between a remote sender and the capturer, and
   // thus equals to the corresponding values in the received RTP packets,
   // subjected to possible interpolations.