Refactor: Clear m_axObjectCache when AXObject detaches

Source/modules/accessibility/AXImageMapLink.cpp

 /*
  * Copyright (C) 2008 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 "config.h"
 #include "modules/accessibility/AXImageMapLink.h"
 
 #include "modules/accessibility/AXLayoutObject.h"
 #include "modules/accessibility/AXObjectCacheImpl.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
-AXImageMapLink::AXImageMapLink(AXObjectCacheImpl* axObjectCache)
+AXImageMapLink::AXImageMapLink(AXObjectCacheImpl& axObjectCache)
     : AXMockObject(axObjectCache)
     , m_areaElement(nullptr)
     , m_mapElement(nullptr)
 {
 }
 
 AXImageMapLink::~AXImageMapLink()
 {
 }
 
 void AXImageMapLink::detachFromParent()
 {
     AXMockObject::detachFromParent();
     m_areaElement = nullptr;
     m_mapElement = nullptr;
 }
 
-PassRefPtr<AXImageMapLink> AXImageMapLink::create(AXObjectCacheImpl* axObjectCache)
+PassRefPtr<AXImageMapLink> AXImageMapLink::create(AXObjectCacheImpl& axObjectCache)
 {
     return adoptRef(new AXImageMapLink(axObjectCache));
 }
 
 AXObject* AXImageMapLink::computeParent() const
 {
     if (m_parent)
         return m_parent;
 
     if (!m_mapElement.get() || !m_mapElement->layoutObject())
         return 0;
 
-    return axObjectCache()->getOrCreate(m_mapElement->layoutObject());
+    return axObjectCache().getOrCreate(m_mapElement->layoutObject());
 }
 
 AccessibilityRole AXImageMapLink::roleValue() const
 {
     if (!m_areaElement)
         return LinkRole;
 
     const AtomicString& ariaRole = getAttribute(roleAttr);
     if (!ariaRole.isEmpty())
         return AXObject::ariaRoleToWebCoreRole(ariaRole);
@@ skipping 54 matching lines @@
     else
         layoutObject = m_mapElement->layoutObject();
 
     if (!layoutObject)
         return LayoutRect();
 
     return m_areaElement->computeRect(layoutObject);
 }
 
 } // namespace blink