Bug 1796069 - Remove unused BasicTrackSource. r=padenot

Differential Revision: https://phabricator.services.mozilla.com/D160755

dom/media/MediaStreamTrack.h

@@ -332,29 +332,6 @@ class MediaStreamTrackSource : public nsISupports {
   bool mStopped;
 };
 
-/**
- * Basic implementation of MediaStreamTrackSource that doesn't forward Stop().
- */
-class BasicTrackSource : public MediaStreamTrackSource {
- public:
-  explicit BasicTrackSource(
-      nsIPrincipal* aPrincipal,
-      const MediaSourceEnum aMediaSource = MediaSourceEnum::Other)
-      : MediaStreamTrackSource(aPrincipal, nsString(), TrackingId()),
-        mMediaSource(aMediaSource) {}
-
-  MediaSourceEnum GetMediaSource() const override { return mMediaSource; }
-
-  void Stop() override {}
-  void Disable() override {}
-  void Enable() override {}
-
- protected:
-  ~BasicTrackSource() = default;
-
-  const MediaSourceEnum mMediaSource;
-};
-
 /**
  * Base class that consumers of a MediaStreamTrack can use to get notifications
  * about state changes in the track.