Blink JavaScript shared memory prototype.

Source/wtf/ArrayBufferContents.h

Index: Source/wtf/ArrayBufferContents.h
diff --git a/Source/wtf/ArrayBufferContents.h b/Source/wtf/ArrayBufferContents.h
index edd5ef7346567a8f06f3a99f18cd14608fa84786..ff8b00e276fc2e412d6149c1ac80a55f50685d04 100644
--- a/Source/wtf/ArrayBufferContents.h
+++ b/Source/wtf/ArrayBufferContents.h
@@ -29,10 +29,25 @@
 
 #include "wtf/ArrayBufferDeallocationObserver.h"
 #include "wtf/Noncopyable.h"
+#include "wtf/RefPtr.h"
+#include "wtf/ThreadSafeRefCounted.h"
 #include "wtf/WTFExport.h"
 
 namespace WTF {
 
+class DataHolder : public ThreadSafeRefCounted<DataHolder> {
+    WTF_MAKE_NONCOPYABLE(DataHolder);
+public:
+    DataHolder();
+    ~DataHolder();
+
+    void adopt(void* data, unsigned sizeInBytes, bool shared);
+
+    void* m_data;
+    unsigned m_sizeInBytes;
+    bool m_shared;
+};
+
 class WTF_EXPORT ArrayBufferContents {
     WTF_MAKE_NONCOPYABLE(ArrayBufferContents);
 public:
@@ -49,20 +64,21 @@ public:
     // upon destruction.
     // This constructor will not call observer->StartObserving(), so it is a responsibility
     // of the caller to make sure JS knows about external memory.
-    ArrayBufferContents(void* data, unsigned sizeInBytes, ArrayBufferDeallocationObserver*);
+    ArrayBufferContents(void* data, unsigned sizeInBytes, bool shared, ArrayBufferDeallocationObserver*);
 
     ~ArrayBufferContents();
 
     void clear();
 
-    void* data() const { return m_data; }
-    unsigned sizeInBytes() const { return m_sizeInBytes; }
+    void* data() const { return m_holder->m_data; }
+    unsigned sizeInBytes() const { return m_holder->m_sizeInBytes; }
+    bool shared() const { return m_holder->m_shared; }
 
     void setDeallocationObserver(ArrayBufferDeallocationObserver* observer)
     {
         if (!m_deallocationObserver) {
             m_deallocationObserver = observer;
-            m_deallocationObserver->blinkAllocatedMemory(m_sizeInBytes);
+            m_deallocationObserver->blinkAllocatedMemory(m_holder->m_sizeInBytes);
         }
     }
 
@@ -73,8 +89,7 @@ public:
     static void freeMemory(void*, size_t);
 
 private:
-    void* m_data;
-    unsigned m_sizeInBytes;
+    RefPtr<DataHolder> m_holder;
     ArrayBufferDeallocationObserver* m_deallocationObserver;
 };