Simplify event dispatch in SVGSMILElement

(Re)use EventTarget::EnqueueEvent rather than (re)implementing something
pretty much identical.

Bug: 998526
Change-Id: I79a8d84141e37f485c9b74ee6dc2e4afacda080a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1906150
Auto-Submit: Fredrik Söderquist <fs@opera.com>
Commit-Queue: Stephen Chenney <schenney@chromium.org>
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713864}

third_party/blink/renderer/core/svg/animation/svg_smil_element.cc

@@ -1196,18 +1196,11 @@ void SVGSMILElement::ScheduleRepeatEvents() {
 }
 
 void SVGSMILElement::ScheduleEvent(const AtomicString& event_type) {
-  GetDocument()
-      .GetTaskRunner(TaskType::kDOMManipulation)
-      ->PostTask(FROM_HERE, WTF::Bind(&SVGSMILElement::DispatchPendingEvent,
-                                      WrapPersistent(this), event_type));
-}
-
-void SVGSMILElement::DispatchPendingEvent(const AtomicString& event_type) {
   DCHECK(event_type == event_type_names::kEndEvent ||
          event_type == event_type_names::kBeginEvent ||
          event_type == event_type_names::kRepeatEvent ||
          event_type == "repeatn");
-  DispatchEvent(*Event::Create(event_type));
+  EnqueueEvent(*Event::Create(event_type), TaskType::kDOMManipulation);
 }
 
 bool SVGSMILElement::HasValidTarget() const {

third_party/blink/renderer/core/svg/animation/svg_smil_element.h

@@ -124,7 +124,6 @@ class CORE_EXPORT SVGSMILElement : public SVGElement, public SVGTests {
 
   void ScheduleEvent(const AtomicString& event_type);
   void ScheduleRepeatEvents();
-  void DispatchPendingEvent(const AtomicString& event_type);
 
   virtual bool IsSVGDiscardElement() const { return false; }