Refactor: Clear m_axObjectCache when AXObject detaches

Source/modules/accessibility/AXImageMapLink.h

Index: Source/modules/accessibility/AXImageMapLink.h
diff --git a/Source/modules/accessibility/AXImageMapLink.h b/Source/modules/accessibility/AXImageMapLink.h
index bc21128a8e792ea8b1c764f2316f9172c6711780..87f1310935cb39076d97d3579db889980d18d1f5 100644
--- a/Source/modules/accessibility/AXImageMapLink.h
+++ b/Source/modules/accessibility/AXImageMapLink.h
@@ -40,10 +40,10 @@ class AXObjectCacheImpl;
 class AXImageMapLink final : public AXMockObject {
 
 private:
-    explicit AXImageMapLink(AXObjectCacheImpl*);
+    explicit AXImageMapLink(AXObjectCacheImpl&);
 
 public:
-    static PassRefPtr<AXImageMapLink> create(AXObjectCacheImpl*);
+    static PassRefPtr<AXImageMapLink> create(AXObjectCacheImpl&);
     virtual ~AXImageMapLink();
 
     void setHTMLAreaElement(HTMLAreaElement* element) { m_areaElement = element; }