Cleanup <static_cast>: Switch to toFoo for Accessibility Objects.

Source/core/accessibility/AccessibilityTableRow.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 100 matching lines @@
 
     AccessibilityChildrenVector rowChildren = children();
     if (!rowChildren.size())
         return 0;
 
     // check the first element in the row to see if it is a TH element
     AccessibilityObject* cell = rowChildren[0].get();
     if (!cell->isTableCell())
         return 0;
 
-    RenderObject* cellRenderer = static_cast<AccessibilityTableCell*>(cell)->renderer();
+    RenderObject* cellRenderer = toAccessibilityTableCell(cell)->renderer();
     if (!cellRenderer)
         return 0;
 
     Node* cellNode = cellRenderer->node();
     if (!cellNode || !cellNode->hasTagName(thTag))
         return 0;
 
     return cell;
 }
 
 } // namespace WebCore