Adding cbr support for Opus

webrtc/modules/audio_coding/codecs/audio_encoder.h

Index: webrtc/modules/audio_coding/codecs/audio_encoder.h
diff --git a/webrtc/modules/audio_coding/codecs/audio_encoder.h b/webrtc/modules/audio_coding/codecs/audio_encoder.h
index 47152f9eee1ae4f9532186b1ca69f56bcdf36b8f..13197a6d2667ed7acc206ad88181c8f4c463c034 100644
--- a/webrtc/modules/audio_coding/codecs/audio_encoder.h
+++ b/webrtc/modules/audio_coding/codecs/audio_encoder.h
@@ -135,6 +135,16 @@ class AudioEncoder {
   // returns false.
   virtual bool GetDtx() const;
 
+  // Enables or disables CBR (constant bitrate mode). Returns
+  // true if the codec was able to comply. The default implementation returns
+  // true when asked to disable CBR and false when asked to enable it (meaning
+  // that CBR isn't supported).
+  virtual bool SetCbr(bool enable);
+
+  // Returns the status of CBR. The default implementation always
+  // returns false.
+  virtual bool GetCbr() const;
+
   // Sets the application mode. Returns true if the codec was able to comply.
   // The default implementation just returns false.
   enum class Application { kSpeech, kAudio };