Use backticks not vertical bars to denote variables in comments

Bug: webrtc:12338
Change-Id: I89c8b3a328d04203177522cbdfd9e606fd4bce4c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/228246
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34696}
diff --git a/api/task_queue/task_queue_base.h b/api/task_queue/task_queue_base.h
index 88419ed..d8af6e6 100644
--- a/api/task_queue/task_queue_base.h
+++ b/api/task_queue/task_queue_base.h
@@ -38,7 +38,7 @@
   virtual void Delete() = 0;
 
   // Schedules a task to execute. Tasks are executed in FIFO order.
-  // If |task->Run()| returns true, task is deleted on the task queue
+  // If `task->Run()` returns true, task is deleted on the task queue
   // before next QueuedTask starts executing.
   // When a TaskQueue is deleted, pending tasks will not be executed but they
   // will be deleted. The deletion of tasks may happen synchronously on the