NetEq: Implement Expand::Muted

webrtc/modules/audio_coding/neteq/expand.h

Index: webrtc/modules/audio_coding/neteq/expand.h
diff --git a/webrtc/modules/audio_coding/neteq/expand.h b/webrtc/modules/audio_coding/neteq/expand.h
index 44ced0ab6c21e34c2fa502a81f01402cdcfb2a7a..0feba3693a137af4a7bbaffbd6248c3d9ff72728 100644
--- a/webrtc/modules/audio_coding/neteq/expand.h
+++ b/webrtc/modules/audio_coding/neteq/expand.h
@@ -62,6 +62,10 @@ class Expand {
     return channel_parameters_[channel].mute_factor;
   }
 
+  // Returns true if expansion has been faded down to zero amplitude (for all
+  // channels); false otherwise.
+  bool Muted() const;
+
   // Accessors and mutators.
   virtual size_t overlap_length() const;
   size_t max_lag() const { return max_lag_; }