Support slotchange event

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 534 matching lines @@
     return *root;
 }
 
 #if DCHECK_IS_ON()
 bool Node::needsDistributionRecalc() const
 {
     return shadowIncludingRoot().childNeedsDistributionRecalc();
 }
 #endif
 
+void Node::updateAssignment()
+{
+    Node& root = shadowIncludingRoot();
+    root.recalcAssignment();
+}
+
 void Node::updateDistribution()
 {
     // Extra early out to avoid spamming traces.
     if (inShadowIncludingDocument() && !document().childNeedsDistributionRecalc())
         return;
     TRACE_EVENT0("blink", "Node::updateDistribution");
     ScriptForbiddenScope forbidScript;
     Node& root = shadowIncludingRoot();
     if (root.childNeedsDistributionRecalc())
         root.recalcDistribution();
 }
 
+void Node::recalcAssignment()

[hayato, 2016/04/18 07:16:31]

We do not want to call recalcAssignment recursively.

Given that we call updateAssignment in each DOM mutation, and the result of
assignments is purely a local effect within one node tree, I would rather call
assignV1() (or something else) for a node tree which would be directly affected,
in each DOM mutation.

[yuzuchan, 2016/04/18 09:43:27]

Thanks for the feedback! Done.

+{
+    if (isElementNode()) {
+        if (ElementShadow* shadow = toElement(this)->shadow()) {
+            if (shadow->isV1())
+                shadow->youngestShadowRoot().assignV1();
+        }
+    }
+
+    for (Node* child = firstChild(); child; child = child->nextSibling()) {
+        child->recalcAssignment();
+    }
+
+    for (ShadowRoot* root = youngestShadowRoot(); root; root = root->olderShadowRoot()) {
+        root->recalcAssignment();
+    }
+}
+
 void Node::recalcDistribution()
 {
     DCHECK(childNeedsDistributionRecalc());
 
     if (isElementNode()) {
         if (ElementShadow* shadow = toElement(this)->shadow())
             shadow->distributeIfNeeded();
     }
 
     DCHECK(ScriptForbiddenScope::isScriptForbidden());
@@ skipping 363 matching lines @@
     ElementShadow* parentShadow = parentElementShadow();
     return parentShadow && parentShadow->isV1();
 }
 
 bool Node::isChildOfV0ShadowHost() const
 {
     ElementShadow* parentShadow = parentElementShadow();
     return parentShadow && !parentShadow->isV1();
 }
 
+bool Node::isChildOfSlot() const
+{
+    return parentElement() && isHTMLSlotElement(parentElement());
+}
+
 Element* Node::shadowHost() const
 {
     if (ShadowRoot* root = containingShadowRoot())
         return root->host();
     return nullptr;
 }
 
 ShadowRoot* Node::containingShadowRoot() const
 {
     Node& root = treeScope().rootNode();
@@ skipping 1366 matching lines @@
 
 void showNodePath(const blink::Node* node)
 {
     if (node)
         node->showNodePathForThis();
     else
         fprintf(stderr, "Cannot showNodePath for (nil)\n");
 }
 
 #endif