Rewrite Shadow DOM distribution engine to support partial synchronous distribution for v1

third_party/WebKit/Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) Research In Motion Limited 2010-2011. All rights reserved.
@@ skipping 3821 matching lines @@
             ni->nodeWillBeRemoved(n);
     }
 
     if (LocalFrame* frame = this->frame()) {
         for (Node& n : NodeTraversal::childrenOf(container)) {
             frame->eventHandler().nodeWillBeRemoved(n);
             frame->selection().nodeWillBeRemoved(n);
             frame->page()->dragCaretController().nodeWillBeRemoved(n);
         }
     }
+
+    if (containsV1ShadowTree()) {
+        for (Node& n : NodeTraversal::childrenOf(container))

[esprehn, 2016/05/23 06:41:00]

this traverses the whole subtree again whenever you remove a sutbree. ex. doing
document.body.removeChild() will get traversed again inside here. This should be
done inside ::removedFrom or ::childrenChanged or inside the notifyRemoved walk.

[hayato, 2016/05/24 13:23:38]

My intention to add this check code here, Document::nodeChildrenWillBeRemoved,
is to get this called only *once* per removing a subtree.

As far as I can read, Document::nodeChildrenWillBeRemoved is called from
ContainerNode::removeChildren, which is called only from Node::setTextContent or
something similar.
Let me re-check later, but it looks this is not called recursively.

+            n.checkSlotChangeBeforeRemoved();
+    }
 }
 
 void Document::nodeWillBeRemoved(Node& n)
 {
     for (NodeIterator* ni : m_nodeIterators)
         ni->nodeWillBeRemoved(n);
 
     for (Range* range : m_ranges)
         range->nodeWillBeRemoved(n);
 
     if (LocalFrame* frame = this->frame()) {
         frame->eventHandler().nodeWillBeRemoved(n);
         frame->selection().nodeWillBeRemoved(n);
         frame->page()->dragCaretController().nodeWillBeRemoved(n);
     }
+
+    if (containsV1ShadowTree())
+        n.checkSlotChangeBeforeRemoved();
 }
 
 void Document::dataWillChange(const CharacterData& characterData)
 {
     if (LocalFrame* frame = this->frame())
         frame->selection().dataWillChange(characterData);
 }
 
 void Document::didInsertText(Node* text, unsigned offset, unsigned length)
 {
@@ skipping 2149 matching lines @@
 #ifndef NDEBUG
 using namespace blink;
 void showLiveDocumentInstances()
 {
     Document::WeakDocumentSet& set = Document::liveDocumentSet();
     fprintf(stderr, "There are %u documents currently alive:\n", set.size());
     for (Document* document : set)
         fprintf(stderr, "- Document %p URL: %s\n", document, document->url().getString().utf8().data());
 }
 #endif