Cast: Merge common functionality from audio/video sender into frame_sender.

media/cast/sender/audio_sender.h

Index: media/cast/sender/audio_sender.h
diff --git a/media/cast/sender/audio_sender.h b/media/cast/sender/audio_sender.h
index bef042a24246154d6b3df9a70c3f0db9afa620e7..728da987ad47cedbfd4fa82c107d62e27c1b6424 100644
--- a/media/cast/sender/audio_sender.h
+++ b/media/cast/sender/audio_sender.h
@@ -51,22 +51,17 @@ class AudioSender : public FrameSender,
                    const base::TimeTicks& recorded_time);
 
  protected:
-  // Protected for testability.
-  void OnReceivedCastFeedback(const RtcpCastMessage& cast_feedback);
+  virtual void OnAck(uint32 frame_id) OVERRIDE;
 
  private:
-  // Returns true if there are too many frames in flight, or if the media
-  // duration of the frames in flight would be too high by sending the next
-  // frame.  The latter metric is determined from the given |capture_time|
-  // for the next frame to be encoded and sent.
-  bool ShouldDropNextFrame(base::TimeTicks capture_time) const;
-
   // Called by the |audio_encoder_| with the next EncodedFrame to send.
-  void SendEncodedAudioFrame(scoped_ptr<EncodedFrame> audio_frame);
+  void SendEncodedAudioFrame(int requested_bitrate_before_encode,
+                             scoped_ptr<EncodedFrame> audio_frame);
 
   // Encodes AudioBuses into EncodedFrames.
   scoped_ptr<AudioEncoder> audio_encoder_;
-  const int configured_encoder_bitrate_;
+
+  uint64 samples_sent_to_encoder_;
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<AudioSender> weak_factory_;