Fix for crash occuring when spatial navigation is enabled

Source/core/page/SpatialNavigation.cpp

 /*
  * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Antonio Gomes <tonikitoo@webkit.org>
  *
  * 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
@@ skipping 421 matching lines @@
 }
 
 Node* scrollableEnclosingBoxOrParentFrameForNodeInDirection(FocusDirection direction, Node* node)
 {
     ASSERT(node);
     Node* parent = node;
     do {
         if (parent->isDocumentNode())
             parent = toDocument(parent)->document()->frame()->ownerElement();
         else
-            parent = parent->parentNode();
+            parent = parent->parentOrShadowHostNode();
     } while (parent && !canScrollInDirection(parent, direction) && !parent->isDocumentNode());
 
     return parent;
 }
 
 bool canScrollInDirection(const Node* container, FocusDirection direction)
 {
     ASSERT(container);
     if (container->isDocumentNode())
         return canScrollInDirection(toDocument(container)->frame(), direction);
@@ skipping 277 matching lines @@
     LayoutRect rect = virtualRectForDirection(direction, rectToAbsoluteCoordinates(area->document()->frame(), area->computeRect(area->imageElement()->renderer())), 1);
     return rect;
 }
 
 HTMLFrameOwnerElement* frameOwnerElement(FocusCandidate& candidate)
 {
     return candidate.isFrameOwnerElement() ? static_cast<HTMLFrameOwnerElement*>(candidate.visibleNode) : 0;
 };
 
 } // namespace WebCore