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

Source/core/accessibility/AXNodeObject.cpp

 /*
 * Copyright (C) 2012, 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:
 *
 * 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
@@ skipping 235 matching lines @@
     if (isHTMLDivElement(*node()))
         return DivRole;
     if (isHTMLMeterElement(*node()))
         return MeterRole;
     if (isHTMLOutputElement(*node()))
         return StatusRole;
     if (isHTMLParagraphElement(*node()))
         return ParagraphRole;
     if (isHTMLLabelElement(*node()))
         return LabelRole;
+    if (isHTMLRubyElement(*node()))
+        return RubyRole;
     if (isHTMLDListElement(*node()))
         return DescriptionListRole;
     if (node()->isElementNode() && node()->hasTagName(blockquoteTag))
         return BlockquoteRole;
     if (node()->isElementNode() && node()->hasTagName(figcaptionTag))
         return FigcaptionRole;
     if (node()->isElementNode() && node()->hasTagName(figureTag))
         return FigureRole;
     if (node()->isElementNode() && toElement(node())->isFocusable())
         return GroupRole;
@@ skipping 1506 matching lines @@
     float range = maxValueForRange() - minValueForRange();
     float value = valueForRange();
 
     value += range * (percentChange / 100);
     setValue(String::number(value));
 
     axObjectCache()->postNotification(node(), AXObjectCacheImpl::AXValueChanged, true);
 }
 
 } // namespace blink