--- a/dom/animation/EffectCompositor.cpp
+++ b/dom/animation/EffectCompositor.cpp
@@ -668,32 +668,16 @@ EffectCompositor::MaybeUpdateCascadeResu
   }
 
   UpdateCascadeResults(aBackendType, *effects, aElement, aPseudoType,
                        aStyleContext);
 
   MOZ_ASSERT(!effects->CascadeNeedsUpdate(), "Failed to update cascade state");
 }
 
-/* static */ void
-EffectCompositor::MaybeUpdateCascadeResults(dom::Element* aElement,
-                                            CSSPseudoElementType aPseudoType)
-{
-  EffectSet* effects = EffectSet::GetEffectSet(aElement, aPseudoType);
-  MOZ_ASSERT(effects);
-  if (!effects->CascadeNeedsUpdate()) {
-    return;
-  }
-
-  UpdateCascadeResults(StyleBackendType::Servo, *effects, aElement, aPseudoType,
-                       nullptr);
-
-  MOZ_ASSERT(!effects->CascadeNeedsUpdate(), "Failed to update cascade state");
-}
-
 /* static */ Maybe<NonOwningAnimationTarget>
 EffectCompositor::GetAnimationElementAndPseudoForFrame(const nsIFrame* aFrame)
 {
   // Always return the same object to benefit from return-value optimization.
   Maybe<NonOwningAnimationTarget> result;
 
   CSSPseudoElementType pseudoType =
     aFrame->StyleContext()->GetPseudoType();
@@ -1036,18 +1020,20 @@ EffectCompositor::PreTraverseInSubtree(E
         continue;
       }
 
       elementsWithCascadeUpdates.AppendElement(target);
     }
   }
 
   for (const NonOwningAnimationTarget& target: elementsWithCascadeUpdates) {
-      MaybeUpdateCascadeResults(target.mElement,
-                                target.mPseudoType);
+      MaybeUpdateCascadeResults(StyleBackendType::Servo,
+                                target.mElement,
+                                target.mPseudoType,
+                                nullptr);
   }
   elementsWithCascadeUpdates.Clear();
 
   for (size_t i = 0; i < kCascadeLevelCount; ++i) {
     CascadeLevel cascadeLevel = CascadeLevel(i);
     auto& elementSet = mElementsToRestyle[cascadeLevel];
     for (auto iter = elementSet.Iter(); !iter.Done(); iter.Next()) {
       const NonOwningAnimationTarget& target = getNeededRestyleTarget(iter);
@@ -1127,17 +1113,19 @@ EffectCompositor::PreTraverse(dom::Eleme
     mPresContext->RestyleManager()->AsServo()->
       PostRestyleEventForAnimations(aElement,
                                     cascadeLevel == CascadeLevel::Transitions
                                       ? eRestyle_CSSTransitions
                                       : eRestyle_CSSAnimations);
 
     EffectSet* effects = EffectSet::GetEffectSet(aElement, aPseudoType);
     if (effects) {
-      MaybeUpdateCascadeResults(aElement, aPseudoType);
+      MaybeUpdateCascadeResults(StyleBackendType::Servo,
+                                aElement, aPseudoType,
+                                nullptr);
 
       for (KeyframeEffectReadOnly* effect : *effects) {
         effect->GetAnimation()->WillComposeStyle();
       }
     }
 
     elementSet.Remove(key);
     found = true;

--- a/dom/animation/EffectCompositor.h
+++ b/dom/animation/EffectCompositor.h
@@ -203,24 +203,16 @@ public:
   // This method does NOT detect if other styles that apply above the
   // animation level of the cascade have changed.
   static void
   MaybeUpdateCascadeResults(StyleBackendType aBackendType,
                             dom::Element* aElement,
                             CSSPseudoElementType aPseudoType,
                             nsStyleContext* aStyleContext);
 
-  // Variant of MaybeUpdateCascadeResults for the Servo backend.
-  // The Servo backend doesn't use an nsStyleContext to get the rule node
-  // to traverse the style tree to find !important rules and instead
-  // gets the rule node from |aElement|.
-  static void
-  MaybeUpdateCascadeResults(dom::Element* aElement,
-                            CSSPseudoElementType aPseudoType);
-
   // Helper to fetch the corresponding element and pseudo-type from a frame.
   //
   // For frames corresponding to pseudo-elements, the returned element is the
   // element on which we store the animations (i.e. the EffectSet and/or
   // AnimationCollection), *not* the generated content.
   //
   // Returns an empty result when a suitable element cannot be found including
   // when the frame represents a pseudo-element on which we do not support