--- a/dom/animation/AnimationEffectTiming.h
+++ b/dom/animation/AnimationEffectTiming.h
@@ -12,18 +12,20 @@
 #include "nsStringFwd.h"
 
 namespace mozilla {
 namespace dom {
 
 class AnimationEffectTiming : public AnimationEffectTimingReadOnly
 {
 public:
-  AnimationEffectTiming(const TimingParams& aTiming, KeyframeEffect* aEffect)
-    : AnimationEffectTimingReadOnly(aTiming)
+  AnimationEffectTiming(nsISupports* aParent,
+                        const TimingParams& aTiming,
+                        KeyframeEffect* aEffect)
+    : AnimationEffectTimingReadOnly(aParent, aTiming)
     , mEffect(aEffect) { }
 
   JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
 
   void Unlink() override { mEffect = nullptr; }
 
   void SetDelay(double aDelay);
   void SetEndDelay(double aEndDelay);

--- a/dom/animation/AnimationEffectTimingReadOnly.h
+++ b/dom/animation/AnimationEffectTimingReadOnly.h
@@ -18,18 +18,20 @@
 
 namespace mozilla {
 namespace dom {
 
 class AnimationEffectTimingReadOnly : public nsWrapperCache
 {
 public:
   AnimationEffectTimingReadOnly() = default;
-  explicit AnimationEffectTimingReadOnly(const TimingParams& aTiming)
-    : mTiming(aTiming) { }
+  AnimationEffectTimingReadOnly(nsISupports* aParent,
+                                const TimingParams& aTiming)
+    : mParent(aParent)
+    , mTiming(aTiming) { }
 
   NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(AnimationEffectTimingReadOnly)
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(AnimationEffectTimingReadOnly)
 
 protected:
   virtual ~AnimationEffectTimingReadOnly() = default;
 
 public:

--- a/dom/animation/KeyframeEffect.cpp
+++ b/dom/animation/KeyframeEffect.cpp
@@ -75,17 +75,18 @@ NS_IMPL_ADDREF_INHERITED(KeyframeEffectR
 NS_IMPL_RELEASE_INHERITED(KeyframeEffectReadOnly, AnimationEffectReadOnly)
 
 KeyframeEffectReadOnly::KeyframeEffectReadOnly(
   nsIDocument* aDocument,
   Element* aTarget,
   CSSPseudoElementType aPseudoType,
   const TimingParams& aTiming)
   : KeyframeEffectReadOnly(aDocument, aTarget, aPseudoType,
-                           new AnimationEffectTimingReadOnly(aTiming))
+                           new AnimationEffectTimingReadOnly(aDocument,
+                                                             aTiming))
 {
 }
 
 KeyframeEffectReadOnly::KeyframeEffectReadOnly(
   nsIDocument* aDocument,
   Element* aTarget,
   CSSPseudoElementType aPseudoType,
   AnimationEffectTimingReadOnly* aTiming)
@@ -1338,17 +1339,17 @@ KeyframeEffectReadOnly::SetPerformanceWa
 //
 //---------------------------------------------------------------------
 
 KeyframeEffect::KeyframeEffect(nsIDocument* aDocument,
                                Element* aTarget,
                                CSSPseudoElementType aPseudoType,
                                const TimingParams& aTiming)
   : KeyframeEffectReadOnly(aDocument, aTarget, aPseudoType,
-                           new AnimationEffectTiming(aTiming, this))
+                           new AnimationEffectTiming(aDocument, aTiming, this))
 {
 }
 
 JSObject*
 KeyframeEffect::WrapObject(JSContext* aCx,
                            JS::Handle<JSObject*> aGivenProto)
 {
   return KeyframeEffectBinding::Wrap(aCx, this, aGivenProto);