WebAudio: Remove AudioNode::RefType.

Source/modules/webaudio/AudioBufferSourceNode.h

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 112 matching lines @@
 
     // Granular playback
     bool m_isGrain;
     double m_grainOffset; // in seconds
     double m_grainDuration; // in seconds
 
     // totalPitchRate() returns the instantaneous pitch rate (non-time preserving).
     // It incorporates the base pitch rate, any sample-rate conversion factor from the buffer, and any doppler shift from an associated panner node.
     double totalPitchRate();
 
-    // We optionally keep track of a panner node which has a doppler shift that is incorporated into
-    // the pitch rate. We manually manage ref-counting because we want to use RefTypeConnection.
-    PannerNode* m_pannerNode;
+    // We optionally keep track of a panner node which has a doppler shift that
+    // is incorporated into the pitch rate.
+    // This RefPtr is connection reference. We must call AudioNode::
+    // makeConnection() after ref(), and call AudioNode::breakConnection()
+    // before deref().
+    RefPtr<PannerNode> m_pannerNode;
 
     // This synchronizes process() with setBuffer() which can cause dynamic channel count changes.
     mutable Mutex m_processLock;
 };
 
 } // namespace WebCore
 
 #endif // AudioBufferSourceNode_h