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

Bug: webrtc:12338
Change-Id: I72fcb505a92f03b2ace7160ee33d555a977eddfd
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/226955
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34587}
diff --git a/rtc_base/virtual_socket_server.cc b/rtc_base/virtual_socket_server.cc
index f5e9936..77d6174 100644
--- a/rtc_base/virtual_socket_server.cc
+++ b/rtc_base/virtual_socket_server.cc
@@ -631,7 +631,7 @@
   if (stop_on_idle_ && Thread::Current()->empty()) {
     return false;
   }
-  // Note: we don't need to do anything with |process_io| since we don't have
+  // Note: we don't need to do anything with `process_io` since we don't have
   // any real I/O. Received packets come in the form of queued messages, so
   // Thread will ensure WakeUp is called if another thread sends a
   // packet.
@@ -713,7 +713,7 @@
     RTC_NOTREACHED();
   }
 
-  // If the IP appears in |alternative_address_mapping_|, meaning the test has
+  // If the IP appears in `alternative_address_mapping_`, meaning the test has
   // configured sockets bound to this IP to actually use another IP, replace
   // the IP here.
   auto alternative = alternative_address_mapping_.find(addr->ipaddr());