LibWeb: Update animations in AnimationTimeline::set_current_time

These steps need to be run whenever update_current_time is called and in
a future commit that will be more than just the one place currently.

This also removes the early return in `set_current_time` if the new
`current time` is the same as the old one, since we want to update
animations regardless (e.g. to run pending tasks)

Libraries/LibWeb/Animations/AnimationTimeline.cpp

@@ -24,15 +24,32 @@ Optional<TimeValue> AnimationTimeline::current_time() const
 
 void AnimationTimeline::set_current_time(Optional<TimeValue> value)
 {
-    if (value == m_current_time)
-        return;
-
     if (m_is_monotonically_increasing && m_current_time.has_value() && (!value.has_value() || *value < *m_current_time)) {
         dbgln("AnimationTimeline::set_current_time({}): monotonically increasing timeline can only move forward", value);
         return;
     }
 
     m_current_time = value;
+
+    update_associated_animations_and_dispatch_events();
+}
+
+void AnimationTimeline::update_associated_animations_and_dispatch_events()
+{
+    // https://drafts.csswg.org/web-animations-1/#animation-frame-loop
+    // Note: Due to the hierarchical nature of the timing model, updating the current time of a timeline also involves:
+    // - Updating the current time of any animations associated with the timeline.
+    // - Running the update an animation's finished state procedure for any animations whose current time has been
+    //   updated.
+    // - Queueing animation events for any such animations.
+    for (auto& animation : m_associated_animations)
+        animation.update();
+
+    auto animations = GC::RootVector<GC::Ref<Animations::Animation>> { heap() };
+    for (auto& animation : m_associated_animations)
+        animations.append(animation);
+    for (auto& animation : animations)
+        m_associated_document->dispatch_events_for_animation_if_necessary(animation);
 }
 
 // https://drafts.csswg.org/web-animations-2/#timeline-duration

Libraries/LibWeb/Animations/AnimationTimeline.h

@@ -54,6 +54,7 @@ protected:
     virtual void finalize() override;
 
     void set_current_time(Optional<TimeValue> value);
+    void update_associated_animations_and_dispatch_events();
 
     // https://www.w3.org/TR/web-animations-1/#dom-animationtimeline-currenttime
     Optional<TimeValue> m_current_time {};

Libraries/LibWeb/DOM/Document.cpp

@@ -6100,25 +6100,9 @@ void Document::update_animations_and_send_events(double timestamp)
     {
         HTML::TemporaryExecutionContext temporary_execution_context { realm() };
         // 1. Update the current time of all timelines associated with doc passing now as the timestamp.
-        //
-        // Note: Due to the hierarchical nature of the timing model, updating the current time of a timeline also involves:
-        // - Updating the current time of any animations associated with the timeline.
-        // - Running the update an animation’s finished state procedure for any animations whose current time has been
-        //   updated.
-        // - Queueing animation events for any such animations.
-        for (auto const& timeline : timelines_to_update) {
+        for (auto const& timeline : timelines_to_update)
             timeline->update_current_time(timestamp);
 
-            for (auto& animation : timeline->associated_animations())
-                animation.update();
-
-            auto animations = GC::RootVector<GC::Ref<Animations::Animation>> { heap() };
-            for (auto& animation : timeline->associated_animations())
-                animations.append(animation);
-            for (auto& animation : animations)
-                dispatch_events_for_animation_if_necessary(animation);
-        }
-
         // 2. Remove replaced animations for doc.
         remove_replaced_animations();
 

Libraries/LibWeb/DOM/Document.h

@@ -824,6 +824,7 @@ public:
     };
     void append_pending_animation_event(PendingAnimationEvent const&);
     void update_animations_and_send_events(double timestamp);
+    void dispatch_events_for_animation_if_necessary(GC::Ref<Animations::Animation>);
     void remove_replaced_animations();
 
     WebIDL::ExceptionOr<Vector<GC::Ref<Animations::Animation>>> get_animations();
@@ -1146,7 +1147,6 @@ private:
     Element* find_a_potential_indicated_element(FlyString const& fragment) const;
 
     void dispatch_events_for_transition(GC::Ref<CSS::CSSTransition>);
-    void dispatch_events_for_animation_if_necessary(GC::Ref<Animations::Animation>);
 
     template<typename GetNotifier, typename... Args>
     void notify_each_document_observer(GetNotifier&& get_notifier, Args&&... args)

Libraries/LibWeb/Internals/InternalAnimationTimeline.cpp

@@ -17,22 +17,12 @@ GC_DEFINE_ALLOCATOR(InternalAnimationTimeline);
 
 void InternalAnimationTimeline::update_current_time(double)
 {
-    // Do nothing
+    update_associated_animations_and_dispatch_events();
 }
 
 void InternalAnimationTimeline::set_time(Optional<double> time)
 {
     set_current_time(time.map([](double value) -> Animations::TimeValue { return { Animations::TimeValue::Type::Milliseconds, value }; }));
-
-    // https://drafts.csswg.org/web-animations-1/#animation-frame-loop
-    // Note: Due to the hierarchical nature of the timing model, updating the current time of a timeline also involves:
-    // - Updating the current time of any animations associated with the timeline.
-    // - Running the update an animation's finished state procedure for any animations whose current time has been
-    //   updated.
-    // - Queueing animation events for any such animations.
-    // NB: This mirrors what the event loop does for DocumentTimeline in Document::update_animations_and_send_events().
-    for (auto& animation : associated_animations())
-        animation.update();
 }
 
 InternalAnimationTimeline::InternalAnimationTimeline(JS::Realm& realm, GC::Ref<DOM::Document> document)