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

Bug: webrtc:12338
Change-Id: I02613d9fca45d00e2477f334b7a0416e7912e26b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227037
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34621}
diff --git a/modules/audio_coding/neteq/time_stretch.h b/modules/audio_coding/neteq/time_stretch.h
index 17ea4ec..998d080 100644
--- a/modules/audio_coding/neteq/time_stretch.h
+++ b/modules/audio_coding/neteq/time_stretch.h
@@ -58,7 +58,7 @@
                       size_t* length_change_samples);
 
  protected:
-  // Sets the parameters |best_correlation| and |peak_index| to suitable
+  // Sets the parameters `best_correlation` and `peak_index` to suitable
   // values when the signal contains no active speech. This method must be
   // implemented by the sub-classes.
   virtual void SetParametersForPassiveSpeech(size_t input_length,
@@ -91,13 +91,13 @@
   const BackgroundNoise& background_noise_;
   int16_t max_input_value_;
   int16_t downsampled_input_[kDownsampledLen];
-  // Adding 1 to the size of |auto_correlation_| because of how it is used
+  // Adding 1 to the size of `auto_correlation_` because of how it is used
   // by the peak-detection algorithm.
   int16_t auto_correlation_[kCorrelationLen + 1];
 
  private:
-  // Calculates the auto-correlation of |downsampled_input_| and writes the
-  // result to |auto_correlation_|.
+  // Calculates the auto-correlation of `downsampled_input_` and writes the
+  // result to `auto_correlation_`.
   void AutoCorrelation();
 
   // Performs a simple voice-activity detection based on the input parameters.