Added check for leaking AXObjects

Source/modules/accessibility/AXObject.h

 /*
  * Copyright (C) 2008, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nuanti Ltd.
  *
  * 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.
@@ skipping 360 matching lines @@
 
         bool isNull() const { return !start && !length; }
     };
 
 protected:
     AXObject(AXObjectCacheImpl*);
 
 public:
     virtual ~AXObject();
 
+    static unsigned instanceCount() { return s_instanceCount; }
+
     // After constructing an AXObject, it must be given a
     // unique ID, then added to AXObjectCacheImpl, and finally init() must
     // be called last.
     void setAXObjectID(AXID axObjectID) { m_id = axObjectID; }
     virtual void init() { }
 
     // When the corresponding WebCore object that this AXObject
     // wraps is deleted, it must be detached.
     virtual void detach();
     virtual bool isDetached() const;
@@ skipping 395 matching lines @@
 
     AXObjectCacheImpl* m_axObjectCache;
 
     // Updates the cached attribute values. This may be recursive, so to prevent deadlocks,
     // functions called here may only search up the tree (ancestors), not down.
     void updateCachedAttributeValuesIfNeeded() const;
 
 private:
     static bool includesARIAWidgetRole(const String&);
     static bool hasInteractiveARIAAttribute(const Element&);
+
+    static unsigned s_instanceCount;
 };
 
 #define DEFINE_AX_OBJECT_TYPE_CASTS(thisType, predicate) \
     DEFINE_TYPE_CASTS(thisType, AXObject, object, object->predicate, object.predicate)
 
 } // namespace blink
 
 #endif // AXObject_h