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/stats/rtc_stats_report.h b/api/stats/rtc_stats_report.h
index 0fe5ce9..a26db86 100644
--- a/api/stats/rtc_stats_report.h
+++ b/api/stats/rtc_stats_report.h
@@ -30,7 +30,7 @@
 namespace webrtc {
 
 // A collection of stats.
-// This is accessible as a map from |RTCStats::id| to |RTCStats|.
+// This is accessible as a map from `RTCStats::id` to `RTCStats`.
 class RTC_EXPORT RTCStatsReport final
     : public rtc::RefCountedNonVirtual<RTCStatsReport> {
  public:
@@ -71,8 +71,8 @@
   const RTCStats* Get(const std::string& id) const;
   size_t size() const { return stats_.size(); }
 
-  // Gets the stat object of type |T| by ID, where |T| is any class descending
-  // from |RTCStats|.
+  // Gets the stat object of type `T` by ID, where `T` is any class descending
+  // from `RTCStats`.
   // Returns null if there is no stats object for the given ID or it is the
   // wrong type.
   template <typename T>
@@ -85,17 +85,17 @@
   }
 
   // Removes the stats object from the report, returning ownership of it or null
-  // if there is no object with |id|.
+  // if there is no object with `id`.
   std::unique_ptr<const RTCStats> Take(const std::string& id);
-  // Takes ownership of all the stats in |other|, leaving it empty.
+  // Takes ownership of all the stats in `other`, leaving it empty.
   void TakeMembersFrom(rtc::scoped_refptr<RTCStatsReport> other);
 
   // Stats iterators. Stats are ordered lexicographically on |RTCStats::id|.
   ConstIterator begin() const;
   ConstIterator end() const;
 
-  // Gets the subset of stats that are of type |T|, where |T| is any class
-  // descending from |RTCStats|.
+  // Gets the subset of stats that are of type `T`, where `T` is any class
+  // descending from `RTCStats`.
   template <typename T>
   std::vector<const T*> GetStatsOfType() const {
     std::vector<const T*> stats_of_type;