Remove nonlinear beamformer API from APM

This CL removes the remaining beamformer parts from the APM.

Bug: webrtc:9402
Change-Id: I9ab2795bd2813d17166ed0925125257b82d98a74
Reviewed-on: https://webrtc-review.googlesource.com/83340
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Reviewed-by: Minyue Li <minyue@webrtc.org>
Commit-Queue: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23694}
diff --git a/modules/audio_processing/audio_processing_impl.h b/modules/audio_processing/audio_processing_impl.h
index f0f823f..d97e676 100644
--- a/modules/audio_processing/audio_processing_impl.h
+++ b/modules/audio_processing/audio_processing_impl.h
@@ -31,21 +31,18 @@
 
 class ApmDataDumper;
 class AudioConverter;
-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 webrtc::Config& config);
-  // AudioProcessingImpl takes ownership of capture post processor and
-  // beamformer.
+  // AudioProcessingImpl takes ownership of capture post processor.
   AudioProcessingImpl(const webrtc::Config& config,
                       std::unique_ptr<CustomProcessing> capture_post_processor,
                       std::unique_ptr<CustomProcessing> render_pre_processor,
                       std::unique_ptr<EchoControlFactory> echo_control_factory,
-                      rtc::scoped_refptr<EchoDetector> echo_detector,
-                      NonlinearBeamformer* beamformer);
+                      rtc::scoped_refptr<EchoDetector> echo_detector);
   ~AudioProcessingImpl() override;
   int Initialize() override;
   int Initialize(int capture_input_sample_rate_hz,