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

Source/core/accessibility/AccessibilityTableCell.h

Index: Source/core/accessibility/AccessibilityTableCell.h
diff --git a/Source/core/accessibility/AccessibilityTableCell.h b/Source/core/accessibility/AccessibilityTableCell.h
index 844c56ab59eb006746d041ceec9006ceecd2d464..46959f41dcc6c9c7e10489869cb34afb1cd94e3e 100644
--- a/Source/core/accessibility/AccessibilityTableCell.h
+++ b/Source/core/accessibility/AccessibilityTableCell.h
@@ -60,6 +60,21 @@ private:
     virtual bool computeAccessibilityIsIgnored() const OVERRIDE;
 };
 
+inline AccessibilityTableCell* toAccessibilityTableCell(AccessibilityObject* object)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isTableCell());
+    return static_cast<AccessibilityTableCell*>(object);
+}
+
+inline const AccessibilityTableCell* toAccessibilityTableCell(const AccessibilityObject* object)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isTableCell());
+    return static_cast<const AccessibilityTableCell*>(object);
+}
+
+// This will catch anyone doing an unnecessary cast.
+void toAccessibilityTableCell(const AccessibilityTableCell*);
+
 } // namespace WebCore
 
 #endif // AccessibilityTableCell_h