Added support for header and footer inside other sections, according to HTML API Mappings 1.0.

third_party/WebKit/Source/modules/accessibility/AXLayoutObject.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 700 matching lines @@
 
         // text elements that are just empty whitespace should not be returned
         // FIXME(dmazzoni): we probably shouldn't ignore this if the style is 'pre', or similar...
         if (layoutText->text().impl()->containsOnlyWhitespace()) {
             if (ignoredReasons)
                 ignoredReasons->append(IgnoredReason(AXEmptyText));
             return true;
         }
         return false;
     }
+
     if (isHeading())
         return false;
 
     if (isLandmarkRelated())
         return false;
 
+    // Header and footer tags may also be exposed as landmark roles but not always.
+    if (getNode() && (getNode()->hasTagName(headerTag) || getNode()->hasTagName(footerTag)))
+        return false;
+
     if (isLink())
         return false;
 
     // all controls are accessible
     if (isControl())
         return false;
 
     if (ariaRoleAttribute() != UnknownRole)
         return false;
 
@@ skipping 1881 matching lines @@
                     result.unite(labelRect);
                 }
             }
         }
     }
 
     return result;
 }
 
 } // namespace blink