Refactor: Clear m_axObjectCache when AXObject detaches

Source/modules/accessibility/AXTableColumn.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 20 matching lines @@
 
 #include "core/layout/LayoutTableCell.h"
 #include "modules/accessibility/AXObjectCacheImpl.h"
 #include "modules/accessibility/AXTableCell.h"
 
 
 namespace blink {
 
 using namespace HTMLNames;
 
-AXTableColumn::AXTableColumn(AXObjectCacheImpl* axObjectCache)
+AXTableColumn::AXTableColumn(AXObjectCacheImpl& axObjectCache)
     : AXMockObject(axObjectCache)
 {
 }
 
 AXTableColumn::~AXTableColumn()
 {
 }
 
-PassRefPtr<AXTableColumn> AXTableColumn::create(AXObjectCacheImpl* axObjectCache)
+PassRefPtr<AXTableColumn> AXTableColumn::create(AXObjectCacheImpl& axObjectCache)
 {
     return adoptRef(new AXTableColumn(axObjectCache));
 }
 
 
 void AXTableColumn::setParent(AXObject* parent)
 {
     AXMockObject::setParent(parent);
 
     clearChildren();
@@ skipping 33 matching lines @@
     for (; tableSection; tableSection = table->sectionBelow(tableSection, SkipEmptySections)) {
         unsigned numCols = tableSection->numColumns();
         if (m_columnIndex >= numCols)
             continue;
         unsigned numRows = tableSection->numRows();
         for (unsigned r = 0; r < numRows; r++) {
             LayoutTableCell* layoutCell = tableSection->primaryCellAt(r, m_columnIndex);
             if (!layoutCell)
                 continue;
 
-            AXObject* cell = axObjectCache()->getOrCreate(layoutCell->node());
+            AXObject* cell = axObjectCache().getOrCreate(layoutCell->node());
             if (!cell || !cell->isTableCell() || headers.contains(cell))
                 continue;
 
             if (toAXTableCell(cell)->scanToDecideHeaderRole() == ColumnHeaderRole)
                 headers.append(cell);
         }
     }
 }
 
 AXObject* AXTableColumn::headerObject()
@@ skipping 39 matching lines @@
         // make sure the last one isn't the same as this one (rowspan cells)
         if (m_children.size() > 0 && m_children.last() == cell)
             continue;
 
         m_children.append(cell);
         m_columnRect.unite(cell->elementRect());
     }
 }
 
 } // namespace blink