Add a new role for an iframe element with role=presentation.

Source/modules/accessibility/AXRenderObject.cpp

 /*
 * Copyright (C) 2008 Apple 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 409 matching lines @@
     if (node && node->hasTagName(addressTag))
         return ContentInfoRole;
 
     if (node && node->hasTagName(dialogTag))
         return DialogRole;
 
     // The HTML element should not be exposed as an element. That's what the RenderView element does.
     if (isHTMLHtmlElement(node))
         return IgnoredRole;
 
-    if (node && node->hasTagName(iframeTag))
+    if (node && node->hasTagName(iframeTag)) {
+        const AtomicString& ariaRole = getAttribute(roleAttr);
+        if (ariaRole == "none" || ariaRole == "presentation")
+            return IframePresentationalRole;
         return IframeRole;
+    }
 
     if (isEmbeddedObject())
         return EmbeddedObjectRole;
 
     if (node && node->hasTagName(figcaptionTag))
         return FigcaptionRole;
 
     if (node && node->hasTagName(figureTag))
         return FigureRole;
 
@@ skipping 2043 matching lines @@
         if (label && label->renderer()) {
             LayoutRect labelRect = axObjectCache()->getOrCreate(label)->elementRect();
             result.unite(labelRect);
         }
     }
 
     return result;
 }
 
 } // namespace blink