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/neteq/neteq_controller.h b/api/neteq/neteq_controller.h
index 4c49a0c..2f203f4 100644
--- a/api/neteq/neteq_controller.h
+++ b/api/neteq/neteq_controller.h
@@ -115,13 +115,13 @@
   virtual void SoftReset() = 0;
 
   // Given info about the latest received packet, and current jitter buffer
-  // status, returns the operation. |target_timestamp| and |expand_mutefactor|
-  // are provided for reference. |last_packet_samples| is the number of samples
+  // status, returns the operation. `target_timestamp` and `expand_mutefactor`
+  // are provided for reference. `last_packet_samples` is the number of samples
   // obtained from the last decoded frame. If there is a packet available, it
-  // should be supplied in |packet|. The mode resulting from the last call to
-  // NetEqImpl::GetAudio is supplied in |last_mode|. If there is a DTMF event to
-  // play, |play_dtmf| should be set to true. The output variable
-  // |reset_decoder| will be set to true if a reset is required; otherwise it is
+  // should be supplied in `packet`. The mode resulting from the last call to
+  // NetEqImpl::GetAudio is supplied in `last_mode`. If there is a DTMF event to
+  // play, `play_dtmf` should be set to true. The output variable
+  // `reset_decoder` will be set to true if a reset is required; otherwise it is
   // left unchanged (i.e., it can remain true if it was true before the call).
   virtual NetEq::Operation GetDecision(const NetEqStatus& status,
                                        bool* reset_decoder) = 0;
@@ -144,11 +144,11 @@
   virtual bool SetBaseMinimumDelay(int delay_ms) = 0;
   virtual int GetBaseMinimumDelay() const = 0;
 
-  // These methods test the |cng_state_| for different conditions.
+  // These methods test the `cng_state_` for different conditions.
   virtual bool CngRfc3389On() const = 0;
   virtual bool CngOff() const = 0;
 
-  // Resets the |cng_state_| to kCngOff.
+  // Resets the `cng_state_` to kCngOff.
   virtual void SetCngOff() = 0;
 
   // Reports back to DecisionLogic whether the decision to do expand remains or
@@ -157,7 +157,7 @@
   // sync buffer.
   virtual void ExpandDecision(NetEq::Operation operation) = 0;
 
-  // Adds |value| to |sample_memory_|.
+  // Adds `value` to `sample_memory_`.
   virtual void AddSampleMemory(int32_t value) = 0;
 
   // Returns the target buffer level in ms.