Stop re-signaling a slotchange event

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

Index: third_party/WebKit/Source/core/dom/Node.cpp
diff --git a/third_party/WebKit/Source/core/dom/Node.cpp b/third_party/WebKit/Source/core/dom/Node.cpp
index e7766f1517764202878d2c1e2b76fa3f60166f4a..2cc9d9a34e87bea18e7c6236371af404a1cc491a 100644
--- a/third_party/WebKit/Source/core/dom/Node.cpp
+++ b/third_party/WebKit/Source/core/dom/Node.cpp
@@ -2344,7 +2344,7 @@ void Node::setV0CustomElementState(V0CustomElementState newState) {
     toElement(this)->pseudoStateChanged(CSSSelector::PseudoUnresolved);
 }
 
-void Node::checkSlotChange() {
+void Node::checkSlotChange(SlotChangeType slotChangeType) {
   // Common check logic is used in both cases, "after inserted" and "before
   // removed".
   if (!isSlotable())
@@ -2361,7 +2361,7 @@ void Node::checkSlotChange() {
     // Although DOM Standard requires "assign a slot for node / run assign
     // slotables" at this timing, we skip it as an optimization.
     if (HTMLSlotElement* slot = root->ensureSlotAssignment().findSlot(*this))
-      slot->enqueueSlotChangeEvent();
+      slot->didSlotChange(slotChangeType);
   } else {
     // Relevant DOM Standard:
     // https://dom.spec.whatwg.org/#concept-node-insert
@@ -2375,7 +2375,7 @@ void Node::checkSlotChange() {
       HTMLSlotElement& parentSlot = toHTMLSlotElement(*parent);
       if (ShadowRoot* root = containingShadowRoot()) {
         if (root && root->isV1() && !parentSlot.hasAssignedNodesSlow())

[kochi, 2016/10/31 08:39:13]

BTW (this is not for this review) this |root| is guaranteed
non-null (L2376), so the first check is useless.

-          parentSlot.enqueueSlotChangeEvent();
+          parentSlot.didSlotChange(slotChangeType);
       }
     }
   }