Refactor: Clear m_axObjectCache when AXObject detaches

Source/modules/accessibility/AXTableRow.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/LayoutTableRow.h"
 #include "modules/accessibility/AXObjectCacheImpl.h"
 #include "modules/accessibility/AXTableCell.h"
 
 
 namespace blink {
 
 using namespace HTMLNames;
 
-AXTableRow::AXTableRow(LayoutObject* layoutObject, AXObjectCacheImpl* axObjectCache)
+AXTableRow::AXTableRow(LayoutObject* layoutObject, AXObjectCacheImpl& axObjectCache)
     : AXLayoutObject(layoutObject, axObjectCache)
 {
 }
 
 AXTableRow::~AXTableRow()
 {
 }
 
-PassRefPtr<AXTableRow> AXTableRow::create(LayoutObject* layoutObject, AXObjectCacheImpl* axObjectCache)
+PassRefPtr<AXTableRow> AXTableRow::create(LayoutObject* layoutObject, AXObjectCacheImpl& axObjectCache)
 {
     return adoptRef(new AXTableRow(layoutObject, axObjectCache));
 }
 
 AccessibilityRole AXTableRow::determineAccessibilityRole()
 {
     if (!isTableRow())
         return AXLayoutObject::determineAccessibilityRole();
 
     if ((m_ariaRole = determineAriaRoleAttribute()) != UnknownRole)
@@ skipping 52 matching lines @@
     for (const auto& cell : children()) {
         if (!cell->isTableCell())
             continue;
 
         if (toAXTableCell(cell.get())->scanToDecideHeaderRole() == RowHeaderRole)
             headers.append(cell);
     }
 }
 
 } // namespace blink