Split out event dispatch from SVGSMILElement::UpdateActiveState

This will allow disabling event dispatching altogether in cases where we
can reliably do that (SVGImage). It may also help with not sending
events when seeking the timeline.

Bug: 1021630, 1039886
Change-Id: I82e7b453b3b6abb1d71d064c33c89db7657c8b06
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2007572Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#733399}

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

@@ -456,7 +456,9 @@ void SMILTimeContainer::UpdateIntervals(SMILTime document_time) {
   while (priority_queue_.Min() <= document_time) {
     SVGSMILElement* element = priority_queue_.MinElement();
     element->UpdateInterval(document_time);
-    element->UpdateActiveState(document_time);
+    auto events_to_dispatch = element->UpdateActiveState(document_time);
+    if (events_to_dispatch)
+      element->DispatchEvents(events_to_dispatch);
     SMILTime next_interval_time =
         element->ComputeNextIntervalTime(document_time);
     priority_queue_.Update(next_interval_time, element);

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

@@ -1056,7 +1056,8 @@ bool SVGSMILElement::IsContributing(SMILTime elapsed) const {
          GetActiveState() == kFrozen;
 }
 
-void SVGSMILElement::UpdateActiveState(SMILTime elapsed) {
+SVGSMILElement::EventDispatchMask SVGSMILElement::UpdateActiveState(
+    SMILTime elapsed) {
   const bool was_active = GetActiveState() == kActive;
   active_state_ = DetermineActiveState(interval_, elapsed);
   const bool is_active = GetActiveState() == kActive;
@@ -1064,14 +1065,15 @@ void SVGSMILElement::UpdateActiveState(SMILTime elapsed) {
       interval_has_changed_ && previous_interval_.end == interval_.begin;
   interval_has_changed_ = false;
 
+  unsigned events_to_dispatch = kDispatchNoEvent;
   if ((was_active && !is_active) || interval_restart) {
-    ScheduleEvent(event_type_names::kEndEvent);
+    events_to_dispatch |= kDispatchEndEvent;
     EndedActiveInterval();
   }
 
   if (IsContributing(elapsed)) {
     if (!was_active || interval_restart) {
-      ScheduleEvent(event_type_names::kBeginEvent);
+      events_to_dispatch |= kDispatchBeginEvent;
       StartedActiveInterval();
     }
 
@@ -1079,10 +1081,31 @@ void SVGSMILElement::UpdateActiveState(SMILTime elapsed) {
     if (progress_state.repeat &&
         progress_state.repeat != last_progress_.repeat) {
       NotifyDependentsOnRepeat(progress_state.repeat, elapsed);
-      ScheduleRepeatEvents();
+      events_to_dispatch |= kDispatchRepeatEvent;
     }
     last_progress_ = progress_state;
   }
+  return static_cast<EventDispatchMask>(events_to_dispatch);
+}
+
+void SVGSMILElement::DispatchEvents(EventDispatchMask events_to_dispatch) {
+  // The ordering is based on the usual order in which these events should be
+  // dispatched (and should match the order the flags are set in
+  // UpdateActiveState().
+  if (events_to_dispatch & kDispatchEndEvent) {
+    EnqueueEvent(*Event::Create(event_type_names::kEndEvent),
+                 TaskType::kDOMManipulation);
+  }
+  if (events_to_dispatch & kDispatchBeginEvent) {
+    EnqueueEvent(*Event::Create(event_type_names::kBeginEvent),
+                 TaskType::kDOMManipulation);
+  }
+  if (events_to_dispatch & kDispatchRepeatEvent) {
+    EnqueueEvent(*Event::Create(event_type_names::kRepeatEvent),
+                 TaskType::kDOMManipulation);
+    EnqueueEvent(*Event::Create(AtomicString("repeatn")),
+                 TaskType::kDOMManipulation);
+  }
 }
 
 void SVGSMILElement::UpdateProgressState(SMILTime presentation_time) {
@@ -1202,19 +1225,6 @@ void SVGSMILElement::EndedActiveInterval() {
   RemoveInstanceTimesWithOrigin(end_times_, SMILTimeOrigin::kScript);
 }
 
-void SVGSMILElement::ScheduleRepeatEvents() {
-  ScheduleEvent(event_type_names::kRepeatEvent);
-  ScheduleEvent(AtomicString("repeatn"));
-}
-
-void SVGSMILElement::ScheduleEvent(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");
-  EnqueueEvent(*Event::Create(event_type), TaskType::kDOMManipulation);
-}
-
 bool SVGSMILElement::HasValidTarget() const {
   return targetElement() && targetElement()->InActiveDocument();
 }

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

@@ -82,7 +82,14 @@ class CORE_EXPORT SVGSMILElement : public SVGElement, public SVGTests {
   SMILTime SimpleDuration() const;
 
   void UpdateInterval(SMILTime presentation_time);
-  void UpdateActiveState(SMILTime elapsed);
+  enum EventDispatchMask {
+    kDispatchNoEvent = 0,
+    kDispatchBeginEvent = 1u << 0,
+    kDispatchRepeatEvent = 1u << 1,
+    kDispatchEndEvent = 1u << 2,
+  };
+  EventDispatchMask UpdateActiveState(SMILTime elapsed);
+  void DispatchEvents(EventDispatchMask);
   void UpdateProgressState(SMILTime presentation_time);
   bool IsHigherPriorityThan(const SVGSMILElement* other,
                             SMILTime presentation_time) const;
@@ -102,9 +109,6 @@ class CORE_EXPORT SVGSMILElement : public SVGElement, public SVGTests {
 
   wtf_size_t& PriorityQueueHandle() { return queue_handle_; }
 
-  void ScheduleEvent(const AtomicString& event_type);
-  void ScheduleRepeatEvents();
-
   void Trace(blink::Visitor*) override;
 
  protected: