Add AX role for blockquote 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 370 matching lines @@
 
     if (isHTMLDivElement(node))
         return DivRole;
 
     if (isHTMLFormElement(node))
         return FormRole;
 
     if (node && node->hasTagName(articleTag))
         return ArticleRole;
 
+    if (node && node->hasTagName(blockquoteTag))
+        return BlockquoteRole;
+
     if (node && node->hasTagName(mainTag))
         return MainRole;
 
     if (node && node->hasTagName(navTag))
         return NavigationRole;
 
     if (node && node->hasTagName(asideTag))
         return ComplementaryRole;
 
     if (node && node->hasTagName(sectionTag))
@@ skipping 293 matching lines @@
     // Anything that is content editable should not be ignored.
     // However, one cannot just call node->hasEditableStyle() since that will ask if its parents
     // are also editable. Only the top level content editable region should be exposed.
     if (hasContentEditableAttributeSet())
         return false;
 
     // List items play an important role in defining the structure of lists. They should not be ignored.
     if (roleValue() == ListItemRole)
         return false;
 
+    if (roleValue() == BlockquoteRole)
+        return false;
+
     if (roleValue() == DialogRole)
         return false;
 
     if (roleValue() == FigcaptionRole)
         return false;
 
     if (roleValue() == FigureRole)
         return false;
 
     if (roleValue() == DetailsRole)
@@ skipping 1660 matching lines @@
         if (label && label->renderer()) {
             LayoutRect labelRect = axObjectCache()->getOrCreate(label)->elementRect();
             result.unite(labelRect);
         }
     }
 
     return result;
 }
 
 } // namespace blink