Require use of AudioBus::create() to avoid ref-counting issues

Source/modules/webaudio/AudioDestinationNode.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 49 matching lines @@
     virtual void startRendering() = 0;
 
     AudioSourceProvider* localAudioInputProvider() { return &m_localAudioInputProvider; }
     
 protected:
     // LocalAudioInputProvider allows us to expose an AudioSourceProvider for local/live audio input.
     // If there is local/live audio input, we call set() with the audio input data every render quantum.
     class LocalAudioInputProvider : public AudioSourceProvider {
     public:
         LocalAudioInputProvider()
-            : m_sourceBus(2, AudioNode::ProcessingSizeInFrames) // FIXME: handle non-stereo local input.
+            : m_sourceBus(AudioBus::create(2, AudioNode::ProcessingSizeInFrames)) // FIXME: handle non-stereo local input.
         {
         }
 
         void set(AudioBus* bus)
         {
             if (bus)
-                m_sourceBus.copyFrom(*bus);
+                m_sourceBus->copyFrom(*bus);
         }
 
         // AudioSourceProvider.
         virtual void provideInput(AudioBus* destinationBus, size_t numberOfFrames)
         {
-            bool isGood = destinationBus && destinationBus->length() == numberOfFrames && m_sourceBus.length() == numberOfFrames;
+            bool isGood = destinationBus && destinationBus->length() == numberOfFrames && m_sourceBus->length() == numberOfFrames;
             ASSERT(isGood);
             if (isGood)
-                destinationBus->copyFrom(m_sourceBus);
+                destinationBus->copyFrom(*m_sourceBus);
         }
 
     private:
-        AudioBus m_sourceBus;
+        RefPtr<AudioBus> m_sourceBus;
     };
 
     virtual double tailTime() const OVERRIDE { return 0; }
     virtual double latencyTime() const OVERRIDE { return 0; }
 
     // Counts the number of sample-frames processed by the destination.
     size_t m_currentSampleFrame;
 
     LocalAudioInputProvider m_localAudioInputProvider;
 };
 
 } // namespace WebCore
 
 #endif // AudioDestinationNode_h