Clean up unused AX APIs.

public/web/WebAXEnums.h

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 227 matching lines @@
 
 // Expanded State.
 // These values must match blink::AccessibilityExpanded values.
 // Enforced in AssertMatchingEnums.cpp.
 enum WebAXExpanded {
     WebAXExpandedUndefined = 0,
     WebAXExpandedCollapsed,
     WebAXExpandedExpanded
 };
 
-// Attribute definition values.
-// These values must match blink::AccessibilityOptionalBool values.
-// Enforced in AssertMatchingEnums.cpp.
-enum WebAXOptionalBool {
-    WebAXOptionalBoolUndefined = 0,
-    WebAXOptionalBoolTrue,
-    WebAXOptionalBoolFalse
-};
-
 // These values must match blink::AccessibilityOrientation values.
 // Enforced in AssertMatchingEnums.cpp.
 enum WebAXOrientation {
     WebAXOrientationUndefined = 0,
     WebAXOrientationVertical,
     WebAXOrientationHorizontal,
 };
 
 // Only used by HTML form controls and any other element that has
 // an aria-invalid attribute specified.
@@ skipping 29 matching lines @@
 // because on some platforms this determines how the accessible description
 // is exposed.
 enum WebAXDescriptionFrom {
     WebAXDescriptionFromPlaceholder,
     WebAXDescriptionFromRelatedElement
 };
 
 } // namespace blink
 
 #endif