Pull out the PostFilter to its own NonlinearBeamformer API

webrtc/modules/audio_processing/audio_processing_impl.h

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 18 matching lines @@
 #else
 #include "webrtc/modules/audio_processing/debug.pb.h"
 #endif
 #endif  // WEBRTC_AUDIOPROC_DEBUG_DUMP
 
 namespace webrtc {
 
 class AgcManagerDirect;
 class AudioConverter;
 
-template<typename T>
-class Beamformer;
+class NonlinearBeamformer;
 
 class AudioProcessingImpl : public AudioProcessing {
  public:
   // Methods forcing APM to run in a single-threaded manner.
   // Acquires both the render and capture locks.
   explicit AudioProcessingImpl(const Config& config);
   // AudioProcessingImpl takes ownership of beamformer.
-  AudioProcessingImpl(const Config& config, Beamformer<float>* beamformer);
+  AudioProcessingImpl(const Config& config, NonlinearBeamformer* beamformer);
   virtual ~AudioProcessingImpl();
   int Initialize() override;
   int Initialize(int input_sample_rate_hz,
                  int output_sample_rate_hz,
                  int reverse_sample_rate_hz,
                  ChannelLayout input_layout,
                  ChannelLayout output_layout,
                  ChannelLayout reverse_layout) override;
   int Initialize(const ProcessingConfig& processing_config) override;
   void SetExtraOptions(const Config& config) override;
@@ skipping 285 matching lines @@
 
   struct ApmRenderState {
     std::unique_ptr<AudioConverter> render_converter;
     std::unique_ptr<AudioBuffer> render_audio;
   } render_ GUARDED_BY(crit_render_);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AUDIO_PROCESSING_IMPL_H_