Boilerplate code addition in order to be able to test upcoming AEC additions

webrtc/modules/audio_processing/aec/aec_core_internal.h

Index: webrtc/modules/audio_processing/aec/aec_core_internal.h
diff --git a/webrtc/modules/audio_processing/aec/aec_core_internal.h b/webrtc/modules/audio_processing/aec/aec_core_internal.h
index c05d224f1d5f8a148722fee092a5b16fc9baf99c..6758d0a57825e6ccaa36a43e6506221e9499bf00 100644
--- a/webrtc/modules/audio_processing/aec/aec_core_internal.h
+++ b/webrtc/modules/audio_processing/aec/aec_core_internal.h
@@ -145,6 +145,9 @@ struct AecCore {
   int delay_agnostic_enabled;
   // 1 = extended filter mode enabled, 0 = disabled.
   int extended_filter_enabled;
+  // 1 = next generation aec mode enabled, 0 = disabled.
+  int next_generation_aec_enabled;
+
   // Runtime selection of number of filter partitions.
   int num_partitions;