Added basic framework for AEC3 in the audio processing module

webrtc/modules/audio_processing/aec/aec_core.h

Index: webrtc/modules/audio_processing/aec/aec_core.h
diff --git a/webrtc/modules/audio_processing/aec/aec_core.h b/webrtc/modules/audio_processing/aec/aec_core.h
index 0c491980c2eb7ba09eb9bda328bf87c88057bd10..36cd80080d3451d969513a1e9c9d809293280c4b 100644
--- a/webrtc/modules/audio_processing/aec/aec_core.h
+++ b/webrtc/modules/audio_processing/aec/aec_core.h
@@ -240,7 +240,6 @@ struct AecCore {
   // 1 = extended filter mode enabled, 0 = disabled.
   int extended_filter_enabled;
   // 1 = next generation aec mode enabled, 0 = disabled.
-  int aec3_enabled;
   bool refined_adaptive_filter_enabled;
 
   // Runtime selection of number of filter partitions.
@@ -310,12 +309,6 @@ void WebRtcAec_enable_delay_agnostic(AecCore* self, int enable);
 // enabled and zero if disabled.
 int WebRtcAec_delay_agnostic_enabled(AecCore* self);
 
-// Non-zero enables, zero disables.
-void WebRtcAec_enable_aec3(AecCore* self, int enable);
-
-// Returns 1 if the next generation aec is enabled and zero if disabled.
-int WebRtcAec_aec3_enabled(AecCore* self);
-
 // Turns on/off the refined adaptive filter feature.
 void WebRtcAec_enable_refined_adaptive_filter(AecCore* self, bool enable);