Refactor: Clear m_axObjectCache when AXObject detaches

Source/modules/accessibility/AXSpinButton.h

 /*
  * Copyright (C) 2011 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
@@ skipping 18 matching lines @@
 #include "core/html/shadow/SpinButtonElement.h"
 #include "modules/accessibility/AXMockObject.h"
 
 
 namespace blink {
 
 class AXObjectCacheImpl;
 
 class AXSpinButton final : public AXMockObject {
 public:
-    static PassRefPtr<AXSpinButton> create(AXObjectCacheImpl*);
+    static PassRefPtr<AXSpinButton> create(AXObjectCacheImpl&);
     virtual ~AXSpinButton();
 
     void setSpinButtonElement(SpinButtonElement* spinButton) { m_spinButtonElement = spinButton; }
     void step(int amount);
 
 private:
-    explicit AXSpinButton(AXObjectCacheImpl*);
+    explicit AXSpinButton(AXObjectCacheImpl&);
 
     virtual AccessibilityRole roleValue() const override;
     virtual bool isSpinButton() const override { return true; }
     virtual bool isNativeSpinButton() const override { return true; }
     virtual void addChildren() override;
     virtual LayoutRect elementRect() const override;
     virtual void detach() override;
     virtual void detachFromParent() override;
 
     SpinButtonElement* m_spinButtonElement;
 };
 
 class AXSpinButtonPart final : public AXMockObject {
 public:
-    static PassRefPtr<AXSpinButtonPart> create(AXObjectCacheImpl*);
+    static PassRefPtr<AXSpinButtonPart> create(AXObjectCacheImpl&);
     virtual ~AXSpinButtonPart() { }
 
     bool isIncrementor() const { return m_isIncrementor; }
     void setIsIncrementor(bool value) { m_isIncrementor = value; }
 
 private:
-    explicit AXSpinButtonPart(AXObjectCacheImpl*);
+    explicit AXSpinButtonPart(AXObjectCacheImpl&);
     bool m_isIncrementor : 1;
 
     virtual bool press() const override;
     virtual AccessibilityRole roleValue() const override { return ButtonRole; }
     virtual bool isSpinButtonPart() const override { return true; }
     virtual LayoutRect elementRect() const override;
 };
 
 DEFINE_AX_OBJECT_TYPE_CASTS(AXSpinButton, isNativeSpinButton());
 DEFINE_AX_OBJECT_TYPE_CASTS(AXSpinButtonPart, isSpinButtonPart());
 
 } // namespace blink
 
 #endif // AXSpinButton_h