Piping AutoMuter interface through to ViE API

This is a piece of the AutoMuter effort. A second CL will follow containing modifications to the new API, and tests.

BUG=2436
R=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2331004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4899 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/video_engine/vie_encoder.h b/video_engine/vie_encoder.h
index cbadcd7..8d18bb6 100644
--- a/video_engine/vie_encoder.h
+++ b/video_engine/vie_encoder.h
@@ -162,6 +162,11 @@
   // Disables recording of debugging information.
   virtual int StopDebugRecording();
 
+  // Enables AutoMuter to turn off video when the rate drops below
+  // |threshold_bps|, and turns back on when the rate goes back up above
+  // |threshold_bps| + |window_bps|.
+  virtual void EnableAutoMuting(int threshold_bps, int window_bps);
+
   int channel_id() const { return channel_id_; }
  protected:
   // Called by BitrateObserver.
@@ -216,6 +221,7 @@
 
   // Quality modes callback
   QMVideoSettingsCallback* qm_callback_;
+  bool video_auto_muted_;
 };
 
 }  // namespace webrtc