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_parameters.h b/api/rtp_parameters.h
index a098bad..71ae984 100644
--- a/api/rtp_parameters.h
+++ b/api/rtp_parameters.h
@@ -126,7 +126,7 @@
   RtpCodecCapability();
   ~RtpCodecCapability();
 
-  // Build MIME "type/subtype" string from |name| and |kind|.
+  // Build MIME "type/subtype" string from `name` and `kind`.
   std::string mime_type() const { return MediaTypeToString(kind) + "/" + name; }
 
   // Used to identify the codec. Equivalent to MIME subtype.
@@ -537,7 +537,7 @@
   RtpCodecParameters(const RtpCodecParameters&);
   ~RtpCodecParameters();
 
-  // Build MIME "type/subtype" string from |name| and |kind|.
+  // Build MIME "type/subtype" string from `name` and `kind`.
   std::string mime_type() const { return MediaTypeToString(kind) + "/" + name; }
 
   // Used to identify the codec. Equivalent to MIME subtype.
@@ -562,7 +562,7 @@
   absl::optional<int> num_channels;
 
   // The maximum packetization time to be used by an RtpSender.
-  // If |ptime| is also set, this will be ignored.
+  // If `ptime` is also set, this will be ignored.
   // TODO(deadbeef): Not implemented.
   absl::optional<int> max_ptime;
 
@@ -607,7 +607,7 @@
 
   // Supported Forward Error Correction (FEC) mechanisms. Note that the RED,
   // ulpfec and flexfec codecs used by these mechanisms will still appear in
-  // |codecs|.
+  // `codecs`.
   std::vector<FecMechanism> fec;
 
   bool operator==(const RtpCapabilities& o) const {