Add AX role ,'AXDescriptionList', for dl element(re-land).

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 15 matching lines @@
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
 #include "config.h"
 #include "core/accessibility/AXNodeObject.h"
 
 #include "core/InputTypeNames.h"
 #include "core/accessibility/AXObjectCache.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/Text.h"
+#include "core/html/HTMLDListElement.h"
 #include "core/html/HTMLFieldSetElement.h"
 #include "core/html/HTMLFrameElementBase.h"
 #include "core/html/HTMLInputElement.h"
 #include "core/html/HTMLLabelElement.h"
 #include "core/html/HTMLLegendElement.h"
 #include "core/html/HTMLPlugInElement.h"
 #include "core/html/HTMLSelectElement.h"
 #include "core/html/HTMLTextAreaElement.h"
 #include "core/rendering/RenderObject.h"
 #include "platform/UserGestureIndicator.h"
@@ skipping 192 matching lines @@
     if (isHTMLTextAreaElement(*node()))
         return TextAreaRole;
     if (headingLevel())
         return HeadingRole;
     if (isHTMLDivElement(*node()))
         return DivRole;
     if (isHTMLParagraphElement(*node()))
         return ParagraphRole;
     if (isHTMLLabelElement(*node()))
         return LabelRole;
+    if (isHTMLDListElement(*node()))
+        return DescriptionListRole;
     if (node()->isElementNode() && node()->hasTagName(figcaptionTag))
         return FigcaptionRole;
     if (node()->isElementNode() && node()->hasTagName(figureTag))
         return FigureRole;
     if (node()->isElementNode() && toElement(node())->isFocusable())
         return GroupRole;
     if (isHTMLAnchorElement(*node()) && isClickable())
         return LinkRole;
     if (isHTMLIFrameElement(*node()))
         return IframeRole;
@@ skipping 1463 matching lines @@
     float range = maxValueForRange() - minValueForRange();
     float value = valueForRange();
 
     value += range * (percentChange / 100);
     setValue(String::number(value));
 
     axObjectCache()->postNotification(node(), AXObjectCache::AXValueChanged, true);
 }
 
 } // namespace blink