1 files changed, 35 insertions, 6 deletions

diff --git a/chromium/third_party/blink/renderer/core/animation/css/css_transition.h b/chromium/third_party/blink/renderer/core/animation/css/css_transition.h
index 483b2f0e1cb..07b5debd496 100644
--- a/chromium/third_party/blink/renderer/core/animation/css/css_transition.h
+++ b/chromium/third_party/blink/renderer/core/animation/css/css_transition.h
@@ -6,7 +6,9 @@
 #define THIRD_PARTY_BLINK_RENDERER_CORE_ANIMATION_CSS_CSS_TRANSITION_H_
 
 #include "third_party/blink/renderer/core/animation/animation.h"
+#include "third_party/blink/renderer/core/animation/animation_effect.h"
 #include "third_party/blink/renderer/core/core_export.h"
+#include "third_party/blink/renderer/core/dom/element.h"
 
 namespace blink {
 
@@ -21,20 +23,47 @@ class CORE_EXPORT CSSTransition : public Animation {
 
   bool IsCSSTransition() const final { return true; }
 
+  void ClearOwningElement() final { owning_element_ = nullptr; }
+  Element* OwningElement() const override { return owning_element_; }
+
   AtomicString transitionProperty() const;
   const CSSProperty& TransitionCSSProperty() const {
     return transition_property_.GetCSSProperty();
   }
 
+  // Animation overrides.
+  // Various operations may affect the computed values of properties on
+  // elements. User agents may, as an optimization, defer recomputing these
+  // values until it becomes necessary; however, all operations included in the
+  // programming interfaces defined in the web-animations and css-transitions
+  // specifications, must produce a result consistent with having fully
+  // processed any such pending changes to computed values.  Notably, setting
+  // display:none must update the play state.
+  // https://drafts.csswg.org/css-transitions-2/#requirements-on-pending-style-changes
+  String playState() const override;
+  void Trace(blink::Visitor* visitor) override {
+    Animation::Trace(visitor);
+    visitor->Trace(owning_element_);
+  }
+
+ protected:
+  AnimationEffect::EventDelegate* CreateEventDelegate(
+      Element* target,
+      const AnimationEffect::EventDelegate* old_event_delegate) override;
+
  private:
   PropertyHandle transition_property_;
+  // The owning element of a transition refers to the element or pseudo-element
+  // to which the transition-property property was applied that generated the
+  // animation.
+  Member<Element> owning_element_;
+};
+template <>
+struct DowncastTraits<CSSTransition> {
+  static bool AllowFrom(const Animation& animation) {
+    return animation.IsCSSTransition();
+  }
 };
-
-DEFINE_TYPE_CASTS(CSSTransition,
-                  Animation,
-                  animation,
-                  animation->IsCSSTransition(),
-                  animation.IsCSSTransition());
 
 }  // namespace blink