Adds accessibility role for figcaption tag

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 371 matching lines @@
     // 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;
 
     if (isEmbeddedObject())
         return EmbeddedObjectRole;
 
+    if (node && node->hasTagName(figcaptionTag))
+        return FigcaptionRole;
+
     if (node && node->hasTagName(figureTag))
         return FigureRole;
 
     // 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;
 
@@ skipping 169 matching lines @@
         // aria-hidden is meant to override visibility as the determinant in AX hierarchy inclusion.
         if (equalIgnoringCase(getAttribute(aria_hiddenAttr), "false"))
             return DefaultBehavior;
 
         return IgnoreObject;
     }
 
     return AXObject::defaultObjectInclusion();
 }
 
 bool AXRenderObject::computeAccessibilityIsIgnored() const

[dmazzoni, 2014/09/03 21:26:17]

Note: I just realized you may want to add support for these new roles you added
here.

In particular, I'm worried about a case like this:

<figcaption>
  <div>
    <div>
      Some text
    </div>
  </div>
</figcaption>

The logic here is designed to "ignore" nodes that don't seem to add anything
useful to the accessibility tree. It definitely eliminates multiple nested DIV
elements, for example. If you don't add support, it may eliminate the FIGCAPTION
element - but you should try it and see if that's an issue.
      

 {
 #if ENABLE(ASSERT)
     ASSERT(m_initialized);
 #endif
 
     // Check first if any of the common reasons cause this element to be ignored.
     // Then process other use cases that need to be applied to all the various roles
     // that AXRenderObjects take on.
     AXObjectInclusion decision = defaultObjectInclusion();
     if (decision == IncludeObject)
@@ skipping 1749 matching lines @@
         if (label && label->renderer()) {
             LayoutRect labelRect = axObjectCache()->getOrCreate(label)->elementRect();
             result.unite(labelRect);
         }
     }
 
     return result;
 }
 
 } // namespace blink