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

Source/core/accessibility/AccessibilityMenuListOption.h

 /*
  * Copyright (C) 2010 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 43 matching lines @@
     virtual bool isSelected() const OVERRIDE;
     virtual void setSelected(bool) OVERRIDE;
     virtual bool canSetSelectedAttribute() const OVERRIDE;
     virtual LayoutRect elementRect() const OVERRIDE;
     virtual String stringValue() const OVERRIDE;
     virtual bool computeAccessibilityIsIgnored() const OVERRIDE;
 
     RefPtr<HTMLElement> m_element;
 };
 
+inline AccessibilityMenuListOption* toAccessibilityMenuListOption(AccessibilityObject* object)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isMenuListOption());
+    return static_cast<AccessibilityMenuListOption*>(object);
+}
+
+inline const AccessibilityMenuListOption* toAccessibilityMenuListOption(const AccessibilityObject* object)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isMenuListOption());
+    return static_cast<const AccessibilityMenuListOption*>(object);
+}
+
+// This will catch anyone doing an unnecessary cast.
+void toAccessibilityMenuListOption(const AccessibilityMenuListOption*);
+
 } // namespace WebCore
 
 #endif // AccessibilityMenuListOption_h