Fix focus navigation for nested slot case

third_party/WebKit/Source/core/dom/shadow/SlotScopedTraversal.h

Index: third_party/WebKit/Source/core/dom/shadow/SlotScopedTraversal.h
diff --git a/third_party/WebKit/Source/core/dom/shadow/SlotScopedTraversal.h b/third_party/WebKit/Source/core/dom/shadow/SlotScopedTraversal.h
index fa780b70325d468edf57f07a4bcae56fbab628f2..07031f7edb1eb0034b57a72ce1fa571c9e5de532 100644
--- a/third_party/WebKit/Source/core/dom/shadow/SlotScopedTraversal.h
+++ b/third_party/WebKit/Source/core/dom/shadow/SlotScopedTraversal.h
@@ -5,17 +5,22 @@
 #ifndef SlotScopedTraversal_h
 #define SlotScopedTraversal_h
 
+#include "core/CoreExport.h"
+
 namespace blink {
 
 class Element;
 class HTMLSlotElement;
 
-class SlotScopedTraversal {
+class CORE_EXPORT SlotScopedTraversal {
  public:
   static HTMLSlotElement* findScopeOwnerSlot(const Element&);
-  static Element* nearestAncestorAssignedToSlot(const Element&);
+  static Element* nearestInclusiveAncestorAssignedToSlot(const Element&);
   static Element* next(const Element&);
   static Element* previous(const Element&);
+  static Element* firstAssignedToSlot(HTMLSlotElement&);
+  static Element* lastAssignedToSlot(HTMLSlotElement&);
+
   static bool isSlotScoped(const Element&);
 };