Make the echo detector injectable.

This adds a generic interface for an echo detector, and makes it possible to inject one into the audio processing module.

Bug: webrtc:8732
Change-Id: I30d97aeb829307b2ae9c4dbeb9a3e15ab7ec0912
Reviewed-on: https://webrtc-review.googlesource.com/38900
Commit-Queue: Ivo Creusen <ivoc@webrtc.org>
Reviewed-by: Per Ã…hgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21588}
diff --git a/modules/audio_processing/audio_processing_impl.h b/modules/audio_processing/audio_processing_impl.h
index c05d238..8ece029 100644
--- a/modules/audio_processing/audio_processing_impl.h
+++ b/modules/audio_processing/audio_processing_impl.h
@@ -45,6 +45,7 @@
                       std::unique_ptr<CustomProcessing> capture_post_processor,
                       std::unique_ptr<CustomProcessing> render_pre_processor,
                       std::unique_ptr<EchoControlFactory> echo_control_factory,
+                      std::unique_ptr<EchoDetector> echo_detector,
                       NonlinearBeamformer* beamformer);
   ~AudioProcessingImpl() override;
   int Initialize() override;