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

Source/core/platform/audio/AudioBus.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
@@ skipping 48 matching lines @@
     };
 
     enum ChannelInterpretation {
         Speakers,
         Discrete,
     };
 
     // allocate indicates whether or not to initially have the AudioChannels created with managed storage.
     // Normal usage is to pass true here, in which case the AudioChannels will memory-manage their own storage.
     // If allocate is false then setChannelMemory() has to be called later on for each channel before the AudioBus is useable...
-    AudioBus(unsigned numberOfChannels, size_t length, bool allocate = true);
+    static PassRefPtr<AudioBus> create(unsigned numberOfChannels, size_t length, bool allocate = true);
 
     // Tells the given channel to use an externally allocated buffer.
     void setChannelMemory(unsigned channelIndex, float* storage, size_t length);
 
     // Channels
     unsigned numberOfChannels() const { return m_channels.size(); }
 
     AudioChannel* channel(unsigned channel) { return m_channels[channel].get(); }
     const AudioChannel* channel(unsigned channel) const { return const_cast<AudioBus*>(this)->m_channels[channel].get(); }
     AudioChannel* channelByType(unsigned type);
@@ skipping 62 matching lines @@
     float maxAbsValue() const;
 
     // Makes maximum absolute value == 1.0 (if possible).
     void normalize();
 
     static PassRefPtr<AudioBus> loadPlatformResource(const char* name, float sampleRate);
 
 protected:
     AudioBus() { };
 
+    AudioBus(unsigned numberOfChannels, size_t length, bool allocate);
+
     void speakersCopyFrom(const AudioBus&);
     void discreteCopyFrom(const AudioBus&);
     void speakersSumFrom(const AudioBus&);
     void discreteSumFrom(const AudioBus&);
     void speakersSumFrom5_1_ToMono(const AudioBus&);
 
     size_t m_length;
     Vector<OwnPtr<AudioChannel> > m_channels;
     int m_layout;
     float m_busGain;
     OwnPtr<AudioFloatArray> m_dezipperGainValues;
     bool m_isFirstTime;
     float m_sampleRate; // 0.0 if unknown or N/A
 };
 
 } // WebCore
 
 #endif // AudioBus_h