HTMLDetailsElement should fire a 'toggle' event

Source/core/html/HTMLDetailsElement.cpp

Index: Source/core/html/HTMLDetailsElement.cpp
diff --git a/Source/core/html/HTMLDetailsElement.cpp b/Source/core/html/HTMLDetailsElement.cpp
index e88582f38346562b1a90eb2a2c08632017d8e353..0ae3e6c26dbd737293bfefe4738996b64ff05fe2 100644
--- a/Source/core/html/HTMLDetailsElement.cpp
+++ b/Source/core/html/HTMLDetailsElement.cpp
@@ -47,11 +47,24 @@ PassRefPtr<HTMLDetailsElement> HTMLDetailsElement::create(Document& document)
 
 HTMLDetailsElement::HTMLDetailsElement(Document& document)
     : HTMLElement(detailsTag, document)
+    , m_toggleEventTimer(this, &HTMLDetailsElement::toggleEventTimerFired)
     , m_isOpen(false)
 {
     ScriptWrappable::init(this);
 }
 
+void HTMLDetailsElement::toggleEventTimerFired(Timer<HTMLDetailsElement> *)
+{
+    dispatchEvent(Event::create(EventTypeNames::toggle));
+}
+
+void HTMLDetailsElement::dispatchToggleEventAsync()
+{
+    if (m_toggleEventTimer.isActive())
+        m_toggleEventTimer.stop();
+    m_toggleEventTimer.startOneShot(0, FROM_HERE);
+}
+
 RenderObject* HTMLDetailsElement::createRenderer(RenderStyle*)
 {
     return new RenderBlockFlow(this);
@@ -94,6 +107,10 @@ void HTMLDetailsElement::parseAttribute(const QualifiedName& name, const AtomicS
         m_isOpen = !value.isNull();
         if (m_isOpen == oldValue)
             return;
+
+        // Dispatch toggle event asynchronously.
+        dispatchToggleEventAsync();
+
         Element* content = ensureUserAgentShadowRoot().getElementById(ShadowElementNames::detailsContent());
         ASSERT(content);
         if (m_isOpen)