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/codecs/opus/opus_unittest.cc b/modules/audio_coding/codecs/opus/opus_unittest.cc
index 80cab50..b507a32 100644
--- a/modules/audio_coding/codecs/opus/opus_unittest.cc
+++ b/modules/audio_coding/codecs/opus/opus_unittest.cc
@@ -115,10 +115,10 @@
 
   void TestCbrEffect(bool dtx, int block_length_ms);
 
-  // Prepare |speech_data_| for encoding, read from a hard-coded file.
+  // Prepare `speech_data_` for encoding, read from a hard-coded file.
   // After preparation, |speech_data_.GetNextBlock()| returns a pointer to a
-  // block of |block_length_ms| milliseconds. The data is looped every
-  // |loop_length_ms| milliseconds.
+  // block of `block_length_ms` milliseconds. The data is looped every
+  // `loop_length_ms` milliseconds.
   void PrepareSpeechData(int block_length_ms, int loop_length_ms);
 
   int EncodeDecode(WebRtcOpusEncInst* encoder,
@@ -310,24 +310,24 @@
   // one with an arbitrary size and the other of 1-byte, then stops sending for
   // a certain number of frames.
 
-  // |max_dtx_frames| is the maximum number of frames Opus can stay in DTX.
+  // `max_dtx_frames` is the maximum number of frames Opus can stay in DTX.
   // TODO(kwiberg): Why does this number depend on the encoding sample rate?
   const int max_dtx_frames =
       (encoder_sample_rate_hz_ == 16000 ? 800 : 400) / block_length_ms + 1;
 
-  // We run |kRunTimeMs| milliseconds of pure silence.
+  // We run `kRunTimeMs` milliseconds of pure silence.
   const int kRunTimeMs = 4500;
 
-  // We check that, after a |kCheckTimeMs| milliseconds (given that the CNG in
+  // We check that, after a `kCheckTimeMs` milliseconds (given that the CNG in
   // Opus needs time to adapt), the absolute values of DTX decoded signal are
-  // bounded by |kOutputValueBound|.
+  // bounded by `kOutputValueBound`.
   const int kCheckTimeMs = 4000;
 
 #if defined(OPUS_FIXED_POINT)
   // Fixed-point Opus generates a random (comfort) noise, which has a less
   // predictable value bound than its floating-point Opus. This value depends on
   // input signal, and the time window for checking the output values (between
-  // |kCheckTimeMs| and |kRunTimeMs|).
+  // `kCheckTimeMs` and `kRunTimeMs`).
   const uint16_t kOutputValueBound = 30;
 
 #else
@@ -336,7 +336,7 @@
 
   int time = 0;
   while (time < kRunTimeMs) {
-    // DTX mode is maintained for maximum |max_dtx_frames| frames.
+    // DTX mode is maintained for maximum `max_dtx_frames` frames.
     int i = 0;
     for (; i < max_dtx_frames; ++i) {
       time += block_length_ms;