Implement computedRole and computedName (behind a flag)

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 53 matching lines @@
     WebAXEventTextChanged,
     WebAXEventTextInserted,
     WebAXEventTextRemoved,
     WebAXEventValueChanged
 };
 
 // Accessibility roles.
 // These values must match blink::AccessibilityRole values.
 // Enforced in AssertMatchingEnums.cpp.
 enum WebAXRole {
-    WebAXRoleAlertDialog = 1,
+    WebAXRoleUnknown = 0,
+    WebAXRoleAlertDialog,
     WebAXRoleAlert,
     WebAXRoleAnnotation,
     WebAXRoleApplication,
     WebAXRoleArticle,
     WebAXRoleBanner,
     WebAXRoleBlockquote,
     WebAXRoleBusyIndicator,
     WebAXRoleButton,
     WebAXRoleCanvas,
     WebAXRoleCell,
@@ skipping 90 matching lines @@
     WebAXRoleTable,
     WebAXRoleTextArea,
     WebAXRoleTextField,
     WebAXRoleTime,
     WebAXRoleTimer,
     WebAXRoleToggleButton,
     WebAXRoleToolbar,
     WebAXRoleTreeGrid,
     WebAXRoleTreeItem,
     WebAXRoleTree,
-    WebAXRoleUnknown,
     WebAXRoleUserInterfaceTooltip,
     WebAXRoleWebArea,
     WebAXRoleWindow,
 };
 
 // Accessibility states, used as a bitmask.
 enum WebAXState {
     WebAXStateBusy,
     WebAXStateChecked,
     WebAXStateEnabled,
@@ skipping 47 matching lines @@
 // Enforced in AssertMatchingEnums.cpp.
 enum WebAXOrientation {
     WebAXOrientationUndefined = 0,
     WebAXOrientationVertical,
     WebAXOrientationHorizontal,
 };
 
 } // namespace blink
 
 #endif