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

Bug: webrtc:12338
Change-Id: I85bff694dd2ead83c939c4d1945eff82e1296001
No-Presubmit: True
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227161
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34690}
diff --git a/modules/audio_processing/audio_processing_impl.h b/modules/audio_processing/audio_processing_impl.h
index 686e417..2c22536 100644
--- a/modules/audio_processing/audio_processing_impl.h
+++ b/modules/audio_processing/audio_processing_impl.h
@@ -169,7 +169,7 @@
       const ApmSubmoduleCreationOverrides& overrides);
 
   // Class providing thread-safe message pipe functionality for
-  // |runtime_settings_|.
+  // `runtime_settings_`.
   class RuntimeSettingEnqueuer {
    public:
     explicit RuntimeSettingEnqueuer(
@@ -320,8 +320,8 @@
 
   // Collects configuration settings from public and private
   // submodules to be saved as an audioproc::Config message on the
-  // AecDump if it is attached.  If not |forced|, only writes the current
-  // config if it is different from the last saved one; if |forced|,
+  // AecDump if it is attached.  If not `forced`, only writes the current
+  // config if it is different from the last saved one; if `forced`,
   // writes the config regardless of the last saved.
   void WriteAecDumpConfigMessage(bool forced)
       RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_capture_);