Add a method to inform AudioProcessing that its output will be muted.

R=turaj@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/8559004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5538 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_processing/include/audio_processing.h b/webrtc/modules/audio_processing/include/audio_processing.h
index 82e6e50..d02b30d 100644
--- a/webrtc/modules/audio_processing/include/audio_processing.h
+++ b/webrtc/modules/audio_processing/include/audio_processing.h
@@ -186,6 +186,13 @@
   virtual int set_num_reverse_channels(int channels) = 0;
   virtual int num_reverse_channels() const = 0;
 
+  // Set to true when the output of AudioProcessing will be muted or in some
+  // other way not used. Ideally, the captured audio would still be processed,
+  // but some components may change behavior based on this information.
+  // Default false.
+  virtual void set_output_will_be_muted(bool muted) = 0;
+  virtual bool output_will_be_muted() const = 0;
+
   // Processes a 10 ms |frame| of the primary audio stream. On the client-side,
   // this is the near-end (or captured) audio.
   //