Surface the noise estimate of the NS to be used by other components

webrtc/modules/audio_processing/include/audio_processing.h

Index: webrtc/modules/audio_processing/include/audio_processing.h
diff --git a/webrtc/modules/audio_processing/include/audio_processing.h b/webrtc/modules/audio_processing/include/audio_processing.h
index bf3565d9ffbb748c1d7bba0d22fbd6924cb1ed7e..138259cf9600a56a5028232f1270b617ca4dfa8c 100644
--- a/webrtc/modules/audio_processing/include/audio_processing.h
+++ b/webrtc/modules/audio_processing/include/audio_processing.h
@@ -915,6 +915,9 @@ class NoiseSuppression {
   // which |kUnsupportedFunctionError| is returned.
   virtual float speech_probability() const = 0;
 
+  // Returns the noise estimate per frequency bin averaged over all channels.
+  virtual std::vector<float> NoiseEstimate() = 0;
+
  protected:
   virtual ~NoiseSuppression() {}
 };