Stop re-signaling a slotchange event

third_party/WebKit/Source/core/dom/shadow/SlotAssignment.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/dom/shadow/SlotAssignment.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/ElementTraversal.h"
+#include "core/dom/Node.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/shadow/ElementShadow.h"
 #include "core/dom/shadow/InsertionPoint.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/html/HTMLSlotElement.h"
 
 namespace blink {
 
 void SlotAssignment::slotAdded(HTMLSlotElement& slot) {
   // Relevant DOM Standard:
   // https://dom.spec.whatwg.org/#concept-node-insert
   // 6.4:  Run assign slotables for a tree with node's tree and a set containing
   // each inclusive descendant of node that is a slot.
 
   ++m_slotCount;
   m_needsCollectSlots = true;
 
   if (!m_slotMap->contains(slot.name())) {
     m_slotMap->add(slot.name(), &slot);
     return;
   }
 
   HTMLSlotElement& oldActive = *findSlotByName(slot.name());
   DCHECK_NE(oldActive, slot);
   m_slotMap->add(slot.name(), &slot);
   if (findSlotByName(slot.name()) == oldActive)
     return;
   // |oldActive| is no longer an active slot.
   if (oldActive.findHostChildWithSameSlotName())
-    oldActive.enqueueSlotChangeEvent();
+    oldActive.didSlotChange(SlotChangeType::Initial);
   // TODO(hayato): We should not enqeueue a slotchange event for |oldActive|
   // if |oldActive| was inserted together with |slot|.
   // This could happen if |oldActive| and |slot| are descendants of the inserted
   // node, and |oldActive| is preceding |slot|.
 }
 
 void SlotAssignment::slotRemoved(HTMLSlotElement& slot) {
   DCHECK_GT(m_slotCount, 0u);
   --m_slotCount;
   m_needsCollectSlots = true;
 
   DCHECK(m_slotMap->contains(slot.name()));
   HTMLSlotElement* oldActive = findSlotByName(slot.name());
   m_slotMap->remove(slot.name(), &slot);
   HTMLSlotElement* newActive = findSlotByName(slot.name());
   if (newActive && newActive != oldActive) {
     // |newActive| slot becomes an active slot.
     if (newActive->findHostChildWithSameSlotName())
-      newActive->enqueueSlotChangeEvent();
+      newActive->didSlotChange(SlotChangeType::Initial);
     // TODO(hayato): Prevent a false-positive slotchange.
     // This could happen if more than one slots which have the same name are
     // descendants of the removed node.
   }
 }
 
 bool SlotAssignment::findHostChildBySlotName(
     const AtomicString& slotName) const {
   // TODO(hayato): Avoid traversing children every time.
   for (Node& child : NodeTraversal::childrenOf(m_owner->host())) {
@@ skipping 11 matching lines @@
   // slot.hasAssignedNodesSynchronously.
   bool hasAssignedNodesBefore = (findSlotByName(oldSlotName) == &slot) &&
                                 findHostChildBySlotName(oldSlotName);
 
   m_slotMap->remove(oldSlotName, &slot);
   m_slotMap->add(slot.name(), &slot);
 
   bool hasAssignedNodesAfter = slot.hasAssignedNodesSlow();
 
   if (hasAssignedNodesBefore || hasAssignedNodesAfter)
-    slot.enqueueSlotChangeEvent();
+    slot.didSlotChange(SlotChangeType::Initial);
 }
 
 void SlotAssignment::hostChildSlotNameChanged(const AtomicString& oldValue,
                                               const AtomicString& newValue) {
   if (HTMLSlotElement* slot =
           findSlotByName(HTMLSlotElement::normalizeSlotName(oldValue))) {
-    slot->enqueueSlotChangeEvent();
+    slot->didSlotChange(SlotChangeType::Initial);
     m_owner->owner()->setNeedsDistributionRecalc();
   }
   if (HTMLSlotElement* slot =
           findSlotByName(HTMLSlotElement::normalizeSlotName(newValue))) {
-    slot->enqueueSlotChangeEvent();
+    slot->didSlotChange(SlotChangeType::Initial);
     m_owner->owner()->setNeedsDistributionRecalc();
   }
 }
 
 SlotAssignment::SlotAssignment(ShadowRoot& owner)
     : m_slotMap(DocumentOrderedMap::create()),
       m_owner(&owner),
       m_needsCollectSlots(false),
       m_slotCount(0) {
   DCHECK(owner.isV1());
@@ skipping 63 matching lines @@
   DCHECK_EQ(m_slots.size(), m_slotCount);
 }
 
 DEFINE_TRACE(SlotAssignment) {
   visitor->trace(m_slots);
   visitor->trace(m_slotMap);
   visitor->trace(m_owner);
 }
 
 }  // namespace blink