Refactor: Clear m_axObjectCache when AXObject detaches

Source/modules/accessibility/AXScrollView.cpp

 /*
  * 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 16 matching lines @@
 #include "modules/accessibility/AXScrollView.h"
 
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "modules/accessibility/AXObjectCacheImpl.h"
 #include "modules/accessibility/AXScrollbar.h"
 
 namespace blink {
 
-AXScrollView::AXScrollView(FrameView* view, AXObjectCacheImpl* axObjectCache)
+AXScrollView::AXScrollView(FrameView* view, AXObjectCacheImpl& axObjectCache)
     : AXObject(axObjectCache)
     , m_scrollView(view)
     , m_childrenDirty(false)
 {
 }
 
 AXScrollView::~AXScrollView()
 {
     ASSERT(isDetached());
 }
 
 void AXScrollView::detach()
 {
     AXObject::detach();
     m_scrollView = 0;
 }
 
-PassRefPtr<AXScrollView> AXScrollView::create(FrameView* view, AXObjectCacheImpl* axObjectCache)
+PassRefPtr<AXScrollView> AXScrollView::create(FrameView* view, AXObjectCacheImpl& axObjectCache)
 {
     return adoptRef(new AXScrollView(view, axObjectCache));
 }
 
 AXObject* AXScrollView::scrollBar(AccessibilityOrientation orientation)
 {
     updateScrollbars();
 
     switch (orientation) {
     case AccessibilityOrientationVertical:
@@ skipping 58 matching lines @@
         m_children[pos]->detachFromParent();
         m_children.remove(pos);
     }
 }
 
 AXScrollbar* AXScrollView::addChildScrollbar(Scrollbar* scrollbar)
 {
     if (!scrollbar)
         return 0;
 
-    AXScrollbar* scrollBarObject = toAXScrollbar(axObjectCache()->getOrCreate(scrollbar));
+    AXScrollbar* scrollBarObject = toAXScrollbar(axObjectCache().getOrCreate(scrollbar));
     scrollBarObject->setParent(this);
     m_children.append(scrollBarObject);
     return scrollBarObject;
 }
 
 void AXScrollView::clearChildren()
 {
     AXObject::clearChildren();
     m_verticalScrollbar = nullptr;
     m_horizontalScrollbar = nullptr;
 }
 
 bool AXScrollView::computeAccessibilityIsIgnored(IgnoredReasons* ignoredReasons) const
 {
     // We just want to match whatever's returned by our web area, which is a child of this
     // object. Normally cached attribute values may only search up the tree. We can't just
     // call accessibilityIsIgnored on the web area, because the web area may search up its
     // ancestors and call this function recursively, and we'd loop until a stack overflow.
 
     // Instead, we first update the cached accessibilityIsIgnored value for this node to
     // false, call accessibilityIsIgnored on the web area, then return the mathcing value.
     m_cachedIsIgnored = false;
-    m_lastModificationCount = axObjectCache()->modificationCount();
+    m_lastModificationCount = axObjectCache().modificationCount();
 
     AXObject* webArea = webAreaObject();
     if (!webArea)
         return true;
 
     if (!webArea->accessibilityIsIgnored())
         return false;
 
     if (ignoredReasons)
         return webArea->computeAccessibilityIsIgnored(ignoredReasons);
@@ skipping 15 matching lines @@
 
 AXObject* AXScrollView::webAreaObject() const
 {
     if (!m_scrollView || !m_scrollView->isFrameView())
         return 0;
 
     Document* doc = m_scrollView->frame().document();
     if (!doc || !doc->layoutView())
         return 0;
 
-    return axObjectCache()->getOrCreate(doc);
+    return axObjectCache().getOrCreate(doc);
 }
 
 AXObject* AXScrollView::accessibilityHitTest(const IntPoint& point) const
 {
     AXObject* webArea = webAreaObject();
     if (!webArea)
         return 0;
 
     if (m_horizontalScrollbar && m_horizontalScrollbar->elementRect().contains(point))
         return m_horizontalScrollbar.get();
@@ skipping 20 matching lines @@
 }
 
 AXObject* AXScrollView::computeParent() const
 {
     if (!m_scrollView || !m_scrollView->isFrameView())
         return 0;
 
     // FIXME: Broken for OOPI.
     HTMLFrameOwnerElement* owner = m_scrollView->frame().deprecatedLocalOwner();
     if (owner && owner->layoutObject())
-        return axObjectCache()->getOrCreate(owner);
+        return axObjectCache().getOrCreate(owner);
 
-    return axObjectCache()->getOrCreate(m_scrollView->frame().pagePopupOwner());
+    return axObjectCache().getOrCreate(m_scrollView->frame().pagePopupOwner());
 }
 
 AXObject* AXScrollView::computeParentIfExists() const
 {
     if (!m_scrollView || !m_scrollView->isFrameView())
         return 0;
 
     HTMLFrameOwnerElement* owner = m_scrollView->frame().deprecatedLocalOwner();
     if (owner && owner->layoutObject())
-        return axObjectCache()->get(owner);
+        return axObjectCache().get(owner);
 
-    return axObjectCache()->get(m_scrollView->frame().pagePopupOwner());
+    return axObjectCache().get(m_scrollView->frame().pagePopupOwner());
 }
 
 ScrollableArea* AXScrollView::getScrollableAreaIfScrollable() const
 {
     return m_scrollView;
 }
 
 } // namespace blink