Removing the intelligibility enhancer.

The intelligibility enhancer is always disabled and it is the only non-test
target using the lapped transform in common_audio (which we planned to remove).

Bug: webrtc:9689, webrtc:5298
Change-Id: Ida65d3aa11ac366471e7e5cbc053108b376c67d8
Reviewed-on: https://webrtc-review.googlesource.com/96460
Commit-Queue: Alessio Bazzica <alessiob@webrtc.org>
Reviewed-by: Alex Loiko <aleloi@webrtc.org>
Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Per Ã…hgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24504}
diff --git a/modules/audio_processing/debug.proto b/modules/audio_processing/debug.proto
index ebfb84d..b19f7fe 100644
--- a/modules/audio_processing/debug.proto
+++ b/modules/audio_processing/debug.proto
@@ -47,7 +47,6 @@
 // Contains the configurations of various APM component. A Config message is
 // added when any of the fields are changed.
 message Config {
-  // Next field number 19.
   // Acoustic echo canceler.
   optional bool aec_enabled = 1;
   optional bool aec_delay_agnostic_enabled = 2;
@@ -73,11 +72,12 @@
   // Semicolon-separated string containing experimental feature
   // descriptions.
   optional string experiments_description = 17;
-  // Intelligibility Enhancer.
-  optional bool intelligibility_enhancer_enabled = 18;
+  reserved 18;  // Intelligibility enhancer enabled (deprecated).
   // Pre amplifier.
   optional bool pre_amplifier_enabled = 19;
   optional float pre_amplifier_fixed_gain_factor = 20;
+
+  // Next field number 21.
 }
 
 message Event {