Temporarily removed the analog gain change detection in AEC3

Due to the implementation of the analog AGC in the audio
processing module, the detection for the analog gain done in AEC3
fails on some platforms where there is no analog gain to control.

This CL removes that functionality until the AGC behavior has
been corrected.


Bug: webrtc:7910, chromium:738322
Change-Id: Ibdbe1e02252387dfd94b36ba7471f5c56ae27f48
Reviewed-on: https://chromium-review.googlesource.com/556040
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Commit-Queue: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18850}
diff --git a/webrtc/modules/audio_processing/audio_processing_impl.cc b/webrtc/modules/audio_processing/audio_processing_impl.cc
index e151c43..39fb723 100644
--- a/webrtc/modules/audio_processing/audio_processing_impl.cc
+++ b/webrtc/modules/audio_processing/audio_processing_impl.cc
@@ -1229,10 +1229,9 @@
   }
 
   if (private_submodules_->echo_canceller3) {
-    const int new_agc_level = gain_control()->stream_analog_level();
-    capture_.echo_path_gain_change =
-        abs(capture_.previous_agc_level - new_agc_level) > 5;
-    capture_.previous_agc_level = new_agc_level;
+    // TODO(peah): Reactivate analogue AGC gain detection once the analogue AGC
+    // issues have been addressed.
+    capture_.echo_path_gain_change = false;
     private_submodules_->echo_canceller3->AnalyzeCapture(capture_buffer);
   }
 
@@ -2257,7 +2256,6 @@
       target_direction(target_direction),
       capture_processing_format(kSampleRate16kHz),
       split_rate(kSampleRate16kHz),
-      previous_agc_level(0),
       echo_path_gain_change(false) {}
 
 AudioProcessingImpl::ApmCaptureState::~ApmCaptureState() = default;