Queue custom element attribute reactions for no-op sets, removes

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc.
  * All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
@@ skipping 2494 matching lines @@
     size_t index,
     SynchronizationOfLazyAttribute inSynchronizationOfLazyAttribute) {
   MutableAttributeCollection attributes =
       ensureUniqueElementData().attributes();
   SECURITY_DCHECK(index < attributes.size());
 
   QualifiedName name = attributes[index].name();
   AtomicString valueBeingRemoved = attributes[index].value();
 
   if (!inSynchronizationOfLazyAttribute) {
-    if (!valueBeingRemoved.isNull())
+    if (!valueBeingRemoved.isNull()) {
       willModifyAttribute(name, valueBeingRemoved, nullAtom);
+    } else if (getCustomElementState() == CustomElementState::Custom) {
+      // This would otherwise be enqueued by willModifyAttribute.
+      CustomElement::enqueueAttributeChangedCallback(
+          this, name, valueBeingRemoved, nullAtom);
+    }
   }
 
   if (Attr* attrNode = attrIfExists(name))
     detachAttrNodeFromElementWithValue(attrNode, attributes[index].value());
 
   attributes.remove(index);
 
   if (!inSynchronizationOfLazyAttribute)
     didRemoveAttribute(name, valueBeingRemoved);
 }
@@ skipping 978 matching lines @@
     updateExtraNamedItemRegistration(oldId, newId);
 }
 
 void Element::willModifyAttribute(const QualifiedName& name,
                                   const AtomicString& oldValue,
                                   const AtomicString& newValue) {
   if (name == HTMLNames::nameAttr) {
     updateName(oldValue, newValue);
   }
 
+  if (getCustomElementState() == CustomElementState::Custom) {
+    CustomElement::enqueueAttributeChangedCallback(this, name, oldValue,
+                                                   newValue);
+  }
+
   if (oldValue != newValue) {
     document().styleEngine().attributeChangedForElement(name, *this);
-    if (getCustomElementState() == CustomElementState::Custom)
-      CustomElement::enqueueAttributeChangedCallback(this, name, oldValue,
-                                                     newValue);
-    else if (isUpgradedV0CustomElement())
+    if (isUpgradedV0CustomElement()) {
       V0CustomElement::attributeDidChange(this, name.localName(), oldValue,
                                           newValue);
+    }
   }
 
   if (MutationObserverInterestGroup* recipients =
           MutationObserverInterestGroup::createForAttributesMutation(*this,
                                                                      name))
     recipients->enqueueMutationRecord(
         MutationRecord::createAttributes(this, name, oldValue));
 
   InspectorInstrumentation::willModifyDOMAttr(this, oldValue, newValue);
 }
@@ skipping 571 matching lines @@
 }
 
 DEFINE_TRACE_WRAPPERS(Element) {
   if (hasRareData()) {
     visitor->traceWrappers(elementRareData());
   }
   ContainerNode::traceWrappers(visitor);
 }
 
 }  // namespace blink