Rebuild layout tree in flat tree order.

third_party/WebKit/Source/core/dom/shadow/FlatTreeTraversal.cpp

 /*
  * Copyright (C) 2012 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 88 matching lines @@
                            ? insertion_point.FirstDistributedNode()
                            : insertion_point.LastDistributedNode()))
       return found;
     DCHECK(isHTMLShadowElement(insertion_point) ||
            (isHTMLContentElement(insertion_point) &&
             !insertion_point.HasChildren()));
   }
   return nullptr;
 }
 
-static HTMLSlotElement* FinalDestinationSlotFor(const Node& node) {
-  HTMLSlotElement* slot = node.AssignedSlot();
-  if (!slot)
-    return nullptr;
-  for (HTMLSlotElement* next = slot->AssignedSlot(); next;
-       next = next->AssignedSlot()) {
-    slot = next;
-  }
-  return slot;
-}
-
 // TODO(hayato): This may return a wrong result for a node which is not in a
 // document flat tree.  See FlatTreeTraversalTest's redistribution test for
 // details.
 Node* FlatTreeTraversal::TraverseSiblings(const Node& node,
                                           TraversalDirection direction) {
   if (node.IsChildOfV1ShadowHost())
     return TraverseSiblingsForV1HostChild(node, direction);
 
   if (ShadowWhereNodeCanBeDistributedForV0(node))
     return TraverseSiblingsForV0Distribution(node, direction);
@@ skipping 25 matching lines @@
       DCHECK(assigned_insertion_point);
       return TraverseSiblings(*assigned_insertion_point, direction);
     }
   }
   return nullptr;
 }
 
 Node* FlatTreeTraversal::TraverseSiblingsForV1HostChild(
     const Node& node,
     TraversalDirection direction) {
-  HTMLSlotElement* slot = FinalDestinationSlotFor(node);
+  HTMLSlotElement* slot = node.FinalDestinationSlot();
   if (!slot)
     return nullptr;
   if (Node* sibling_in_distributed_nodes =
           (direction == kTraversalDirectionForward
                ? slot->DistributedNodeNextTo(node)
                : slot->DistributedNodePreviousTo(node)))
     return sibling_in_distributed_nodes;
   return TraverseSiblings(*slot, direction);
 }
 
@@ skipping 12 matching lines @@
 
 ContainerNode* FlatTreeTraversal::TraverseParent(
     const Node& node,
     ParentTraversalDetails* details) {
   // TODO(hayato): Stop this hack for a pseudo element because a pseudo element
   // is not a child of its parentOrShadowHostNode() in a flat tree.
   if (node.IsPseudoElement())
     return node.ParentOrShadowHostNode();
 
   if (node.IsChildOfV1ShadowHost()) {
-    HTMLSlotElement* slot = FinalDestinationSlotFor(node);
+    HTMLSlotElement* slot = node.FinalDestinationSlot();
     if (!slot)
       return nullptr;
     return TraverseParent(*slot);
   }
 
   Element* parent = node.parentElement();
   if (parent && isHTMLSlotElement(parent)) {
     HTMLSlotElement& slot = toHTMLSlotElement(*parent);
     if (slot.SupportsDistribution()) {
       if (!slot.AssignedNodes().IsEmpty())
@@ skipping 185 matching lines @@
 
 Node& FlatTreeTraversal::LastWithinOrSelf(const Node& node) {
   AssertPrecondition(node);
   Node* last_descendant = LastWithin(node);
   Node& result = last_descendant ? *last_descendant : const_cast<Node&>(node);
   AssertPostcondition(&result);
   return result;
 }
 
 }  // namespace blink