Adding role 'RubyRole' in blink to expose HTML Ruby tag.

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 142 matching lines @@
     WebAXRolePopUpButton,
     WebAXRolePre,
     WebAXRolePresentational,
     WebAXRoleProgressIndicator,
     WebAXRoleRadioButton,
     WebAXRoleRadioGroup,
     WebAXRoleRegion,
     WebAXRoleRootWebArea,
     WebAXRoleRowHeader,
     WebAXRoleRow,
+    WebAXRoleRuby,
     WebAXRoleRulerMarker,
     WebAXRoleRuler,
     WebAXRoleSVGRoot,
     WebAXRoleScrollArea,
     WebAXRoleScrollBar,
     WebAXRoleSeamlessWebArea,
     WebAXRoleSearch,
     WebAXRoleSheet,
     WebAXRoleSlider,
     WebAXRoleSliderThumb,
@@ skipping 64 matching lines @@
 // Enforced in AssertMatchingEnums.cpp.
 enum WebAXExpanded {
     WebAXExpandedUndefined = 0,
     WebAXExpandedCollapsed,
     WebAXExpandedExpanded
 };
 
 } // namespace blink
 
 #endif