Make slots in non-shadow trees participate in a flat tree

third_party/WebKit/Source/core/html/HTMLSlotElement.h

 /*
  * Copyright (C) 2015 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.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 28 matching lines @@
 class AssignedNodesOptions;
 
 class CORE_EXPORT HTMLSlotElement final : public HTMLElement {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
   DECLARE_NODE_FACTORY(HTMLSlotElement);
 
   const HeapVector<Member<Node>>& assignedNodes();
   const HeapVector<Member<Node>>& getDistributedNodes();
+  const HeapVector<Member<Node>> getDistributedNodesForBinding();
   const HeapVector<Member<Node>> assignedNodesForBinding(
       const AssignedNodesOptions&);
 
   Node* firstDistributedNode() const {
+    DCHECK(supportsDistribution());
     return m_distributedNodes.isEmpty() ? nullptr
                                         : m_distributedNodes.first().get();
   }
   Node* lastDistributedNode() const {
+    DCHECK(supportsDistribution());
     return m_distributedNodes.isEmpty() ? nullptr
                                         : m_distributedNodes.last().get();
   }
 
   Node* distributedNodeNextTo(const Node&) const;
   Node* distributedNodePreviousTo(const Node&) const;
 
   void appendAssignedNode(Node&);
 
   void resolveDistributedNodes();
@@ skipping 19 matching lines @@
   // shadow host.  This method should be used only when m_assignedNodes is
   // dirty.  e.g. To detect a slotchange event in DOM mutations.
   bool hasAssignedNodesSlow() const;
   bool findHostChildWithSameSlotName() const;
 
   void enqueueSlotChangeEvent();
 
   void clearDistribution();
   void saveAndClearDistribution();
 
-  bool supportsDistribution() const { return isInShadowTree(); }
-  void updateDistributedNodesManually();
+  bool supportsDistribution() const { return isInV1ShadowTree(); }
 
   static AtomicString normalizeSlotName(const AtomicString&);
 
   DECLARE_VIRTUAL_TRACE();
 
  private:
   HTMLSlotElement(Document&);
 
   InsertionNotificationRequest insertedInto(ContainerNode*) final;
   void removedFrom(ContainerNode*) final;
   void willRecalcStyle(StyleRecalcChange) final;
 
   void dispatchSlotChangeEvent();
 
   HeapVector<Member<Node>> m_assignedNodes;
   HeapVector<Member<Node>> m_distributedNodes;
   HeapVector<Member<Node>> m_oldDistributedNodes;
   HeapHashMap<Member<const Node>, size_t> m_distributedIndices;
   bool m_slotchangeEventEnqueued = false;
 };
 
 }  // namespace blink
 
 #endif  // HTMLSlotElement_h