Support the essential part of Shadow DOM v1

third_party/WebKit/Source/core/editing/Position.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2009 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 375 matching lines @@
 
 PositionInComposedTree toPositionInComposedTree(const Position& pos)
 {
     if (pos.isNull())
         return PositionInComposedTree();
 
     if (pos.isOffsetInAnchor()) {
         Node* anchor = pos.anchorNode();
         if (anchor->offsetInCharacters())
             return PositionInComposedTree(anchor, pos.computeOffsetInContainerNode());
-        ASSERT(!isActiveInsertionPoint(*anchor));
+        ASSERT(!anchor->isSlotOrActiveInsertionPoint());
         int offset = pos.computeOffsetInContainerNode();
         Node* child = NodeTraversal::childAt(*anchor, offset);
         if (!child) {
             if (anchor->isShadowRoot())
                 return PositionInComposedTree(anchor->shadowHost(), PositionAnchorType::AfterChildren);
             return PositionInComposedTree(anchor, PositionAnchorType::AfterChildren);
         }
         child->updateDistribution();
-        if (isActiveInsertionPoint(*child)) {
+        if (child->isSlotOrActiveInsertionPoint()) {
             if (anchor->isShadowRoot())
                 return PositionInComposedTree(anchor->shadowHost(), offset);
             return PositionInComposedTree(anchor, offset);
         }
         if (Node* parent = ComposedTreeTraversal::parent(*child))
             return PositionInComposedTree(parent, ComposedTreeTraversal::index(*child));
         // When |pos| isn't appeared in composed tree, we map |pos| to after
         // children of shadow host.
         // e.g. "foo",0 in <progress>foo</progress>
         if (anchor->isShadowRoot())
@@ skipping 124 matching lines @@
 
 void showTree(const blink::Position* pos)
 {
     if (pos)
         pos->showTreeForThis();
     else
         fprintf(stderr, "Cannot showTree for (nil)\n");
 }
 
 #endif