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

Bug: webrtc:12338
Change-Id: I52eb3b6675c4705e22f51b70799ed6139a3b46bc
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227164
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34686}
diff --git a/modules/rtp_rtcp/source/rtp_rtcp_interface.h b/modules/rtp_rtcp/source/rtp_rtcp_interface.h
index 7e644be..e90d866 100644
--- a/modules/rtp_rtcp/source/rtp_rtcp_interface.h
+++ b/modules/rtp_rtcp/source/rtp_rtcp_interface.h
@@ -124,12 +124,12 @@
     // done by RTCP RR acking.
     bool always_send_mid_and_rid = false;
 
-    // If set, field trials are read from |field_trials|, otherwise
+    // If set, field trials are read from `field_trials`, otherwise
     // defaults to  webrtc::FieldTrialBasedConfig.
     const WebRtcKeyValueConfig* field_trials = nullptr;
 
     // SSRCs for media and retransmission, respectively.
-    // FlexFec SSRC is fetched from |flexfec_sender|.
+    // FlexFec SSRC is fetched from `flexfec_sender`.
     uint32_t local_media_ssrc = 0;
     absl::optional<uint32_t> rtx_send_ssrc;
 
@@ -203,7 +203,7 @@
                                             int payload_frequency) = 0;
 
   // Unregisters a send payload.
-  // |payload_type| - payload type of codec
+  // `payload_type` - payload type of codec
   // Returns -1 on failure else 0.
   virtual int32_t DeRegisterSendPayload(int8_t payload_type) = 0;
 
@@ -259,7 +259,7 @@
   virtual void SetMid(const std::string& mid) = 0;
 
   // Sets CSRC.
-  // |csrcs| - vector of CSRCs
+  // `csrcs` - vector of CSRCs
   virtual void SetCsrcs(const std::vector<uint32_t>& csrcs) = 0;
 
   // Turns on/off sending RTX (RFC 4588). The modes can be set as a combination
@@ -355,7 +355,7 @@
   virtual RtcpMode RTCP() const = 0;
 
   // Sets RTCP status i.e on(compound or non-compound)/off.
-  // |method| - RTCP method to use.
+  // `method` - RTCP method to use.
   virtual void SetRTCPStatus(RtcpMode method) = 0;
 
   // Sets RTCP CName (i.e unique identifier).