Storing raw audio sink for default audio track.

talk/app/webrtc/mediastreamprovider.h

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
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  * modification, are permitted provided that the following conditions are met:
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  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 11 matching lines @@
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 #ifndef TALK_APP_WEBRTC_MEDIASTREAMPROVIDER_H_
 #define TALK_APP_WEBRTC_MEDIASTREAMPROVIDER_H_
 
 #include "webrtc/base/basictypes.h"
-#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/scoped_ref_ptr.h"
 
 namespace cricket {
 
 class AudioRenderer;
 class VideoCapturer;
 class VideoRenderer;
 struct AudioOptions;
 struct VideoOptions;
 
 }  // namespace cricket
@@ skipping 25 matching lines @@
 
   // Sets the audio playout volume of a remote audio track with |ssrc|.
   // |volume| is in the range of [0, 10].
   virtual void SetAudioPlayoutVolume(uint32_t ssrc, double volume) = 0;
 
   // Allows for setting a direct audio sink for an incoming audio source.
   // Only one audio sink is supported per ssrc and ownership of the sink is
   // passed to the provider.
   virtual void SetRawAudioSink(
       uint32_t ssrc,
-      rtc::scoped_ptr<webrtc::AudioSinkInterface> sink) = 0;
+      rtc::scoped_refptr<webrtc::AudioSinkInterface> sink) = 0;

[the sun, 2016/01/08 13:14:26]

Assuming we'll be replacing this with shared_ptr once we can use that, is it
then still a good idea to pass by value? scoped_refptr just contains one
pointer, but shared_ptr has at least two. Should we pass by const & instead?

[Taylor Brandstetter, 2016/01/08 19:46:58]

const & would indeed save some unnecessary copying; this is just the pattern I
was used to seeing.

[the sun, 2016/01/11 10:38:27]

For scoped_ptr (and current scoped_ref_ptr) it won't matter since they just
contain a single pointer; the compiler is pretty smart. :) Thanks for updating
though!

[tommi, 2016/01/12 08:58:06]

Passing scoped_refptr by value will trigger an extra pair of AddRef/Release
calls which can mean unnecessary interlocked operations. That + virtual calls,
so should be passed by const ref.  Thanks for catching Fredrik.

 
  protected:
   virtual ~AudioProviderInterface() {}
 };
 
 // This interface is called by VideoRtpSender/Receivers to change the settings
 // of a video track connected to a certain PeerConnection.
 class VideoProviderInterface {
  public:
   virtual bool SetCaptureDevice(uint32_t ssrc,
                                 cricket::VideoCapturer* camera) = 0;
   // Enable/disable the video playout of a remote video track with |ssrc|.
   virtual void SetVideoPlayout(uint32_t ssrc,
                                bool enable,
                                cricket::VideoRenderer* renderer) = 0;
   // Enable sending video on the local video track with |ssrc|.
   virtual void SetVideoSend(uint32_t ssrc,
                             bool enable,
                             const cricket::VideoOptions* options) = 0;
 
  protected:
   virtual ~VideoProviderInterface() {}
 };
 
 }  // namespace webrtc
 
 #endif  // TALK_APP_WEBRTC_MEDIASTREAMPROVIDER_H_