Do not allocate SlotAssignment unless a shadowroot has a slot

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

Index: third_party/WebKit/Source/core/dom/shadow/SlotAssignment.cpp
diff --git a/third_party/WebKit/Source/core/dom/shadow/SlotAssignment.cpp b/third_party/WebKit/Source/core/dom/shadow/SlotAssignment.cpp
index 77627b3807ad1b1505c01aba2403b7f8cc2c01b0..97c17a127441ef3e68bd9c9d31b27b4ae339de5c 100644
--- a/third_party/WebKit/Source/core/dom/shadow/SlotAssignment.cpp
+++ b/third_party/WebKit/Source/core/dom/shadow/SlotAssignment.cpp
@@ -15,7 +15,7 @@
 
 namespace blink {
 
-void SlotAssignment::slotAdded(HTMLSlotElement& slot) {
+void SlotAssignment::didAddSlot(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
@@ -90,8 +90,8 @@ void SlotAssignment::slotRenamed(const AtomicString& oldSlotName,
     slot.didSlotChange(SlotChangeType::Initial);
 }
 
-void SlotAssignment::hostChildSlotNameChanged(const AtomicString& oldValue,
-                                              const AtomicString& newValue) {
+void SlotAssignment::didChangeHostChildSlotName(const AtomicString& oldValue,
+                                                const AtomicString& newValue) {
   if (HTMLSlotElement* slot =
           findSlotByName(HTMLSlotElement::normalizeSlotName(oldValue))) {
     slot->didSlotChange(SlotChangeType::Initial);