Add an accessibility role for the iframe element (re-land).

Source/core/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 372 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))
+        return IframeRole;
+
     // There should only be one banner/contentInfo per page. If header/footer are being used within an article or section
     // then it should not be exposed as whole page's banner/contentInfo
     if (node && node->hasTagName(headerTag) && !isDescendantOfElementType(articleTag) && !isDescendantOfElementType(sectionTag))
         return BannerRole;
     if (node && node->hasTagName(footerTag) && !isDescendantOfElementType(articleTag) && !isDescendantOfElementType(sectionTag))
         return FooterRole;
 
     if (isHTMLAnchorElement(node) && isClickable())
         return LinkRole;
 
@@ skipping 1941 matching lines @@
         if (label && label->renderer()) {
             LayoutRect labelRect = axObjectCache()->getOrCreate(label)->elementRect();
             result.unite(labelRect);
         }
     }
 
     return result;
 }
 
 } // namespace WebCore