Re-land: Ensure that ArrayBuffers actively being used by the Web Audio API cannot be neutered

Source/wtf/ArrayBufferView.h

 /*
  * Copyright (C) 2009 Apple 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 52 matching lines @@
         return m_baseAddress;
     }
 
     unsigned byteOffset() const
     {
         return m_byteOffset;
     }
 
     virtual unsigned byteLength() const = 0;
 
+    void setNeuterable(bool flag) { m_isNeuterable = flag; }
+    bool isNeuterable() const { return m_isNeuterable; }
+
     virtual ~ArrayBufferView();
 
   protected:
     ArrayBufferView(PassRefPtr<ArrayBuffer>, unsigned byteOffset);
 
     inline bool setImpl(ArrayBufferView*, unsigned byteOffset);
 
     inline bool setRangeImpl(const char* data, size_t dataByteLength, unsigned byteOffset);
 
     inline bool zeroRangeImpl(unsigned byteOffset, size_t rangeByteLength);
@@ skipping 38 matching lines @@
         *offset = std::min(buffer->byteLength(), *offset);
         unsigned remainingElements = (buffer->byteLength() - *offset) / sizeof(T);
         *numElements = std::min(remainingElements, *numElements);
     }
 
     virtual void neuter();
 
     // This is the address of the ArrayBuffer's storage, plus the byte offset.
     void* m_baseAddress;
 
-    unsigned m_byteOffset;
+    unsigned m_byteOffset : 31;
+    bool m_isNeuterable : 1;
 
   private:
     friend class ArrayBuffer;
     RefPtr<ArrayBuffer> m_buffer;
     ArrayBufferView* m_prevView;
     ArrayBufferView* m_nextView;
 };
 
 bool ArrayBufferView::setImpl(ArrayBufferView* array, unsigned byteOffset)
 {
@@ skipping 54 matching lines @@
         end = start;
     *offset = static_cast<unsigned>(start);
     *length = static_cast<unsigned>(end - start);
 }
 
 } // namespace WTF
 
 using WTF::ArrayBufferView;
 
 #endif // ArrayBufferView_h