Cheaper thread-safe atomic initialization of static references.

Source/wtf/ArrayBuffer.h

Index: Source/wtf/ArrayBuffer.h
diff --git a/Source/wtf/ArrayBuffer.h b/Source/wtf/ArrayBuffer.h
index af5dbba72382c91bca725e3ea91349512520ba37..e58f53151817c33a0c7323b2ce89f9d14fcd7416 100644
--- a/Source/wtf/ArrayBuffer.h
+++ b/Source/wtf/ArrayBuffer.h
@@ -66,11 +66,11 @@ public:
     bool transfer(ArrayBufferContents&);
     bool isNeutered() { return m_isNeutered; }
 
-    void setDeallocationObserver(ArrayBufferDeallocationObserver* observer)
+    void setDeallocationObserver(ArrayBufferDeallocationObserver& observer)
     {
         m_contents.setDeallocationObserver(observer);
     }
-    void setDeallocationObserverWithoutAllocationNotification(ArrayBufferDeallocationObserver* observer)
+    void setDeallocationObserverWithoutAllocationNotification(ArrayBufferDeallocationObserver& observer)
     {
         m_contents.setDeallocationObserverWithoutAllocationNotification(observer);
     }