--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -593,16 +593,25 @@ nsComputedDOMStyle::DoGetStyleContextNoF
   bool inDocWithShell = true;
   if (!presShell) {
     inDocWithShell = false;
     presShell = aPresShell;
     if (!presShell)
       return nullptr;
   }
 
+  auto pseudoType = CSSPseudoElementType::NotPseudo;
+  if (aPseudo) {
+    pseudoType = nsCSSPseudoElements::
+      GetPseudoType(aPseudo, CSSEnabledState::eIgnoreEnabledState);
+    if (pseudoType >= CSSPseudoElementType::Count) {
+      return nullptr;
+    }
+  }
+
   // XXX the !aElement->IsHTMLElement(nsGkAtoms::area)
   // check is needed due to bug 135040 (to avoid using
   // mPrimaryFrame). Remove it once that's fixed.
   if (inDocWithShell &&
       aStyleType == eAll &&
       !aElement->IsHTMLElement(nsGkAtoms::area)) {
     nsIFrame* frame = nullptr;
     if (aPseudo == nsCSSPseudoElements::before) {
@@ -645,54 +654,45 @@ nsComputedDOMStyle::DoGetStyleContextNoF
   // for the default style, so resolve the style ourselves.
 
   nsPresContext* presContext = presShell->GetPresContext();
   if (!presContext)
     return nullptr;
 
   StyleSetHandle styleSet = presShell->StyleSet();
 
-  auto type = CSSPseudoElementType::NotPseudo;
-  if (aPseudo) {
-    type = nsCSSPseudoElements::
-      GetPseudoType(aPseudo, CSSEnabledState::eIgnoreEnabledState);
-    if (type >= CSSPseudoElementType::Count) {
-      return nullptr;
-    }
-  }
-
   // For Servo, compute the result directly without recursively building up
   // a throwaway style context chain.
   if (ServoStyleSet* servoSet = styleSet->GetAsServo()) {
     StyleRuleInclusion rules = aStyleType == eDefaultOnly
                                ? StyleRuleInclusion::DefaultOnly
                                : StyleRuleInclusion::All;
-    return servoSet->ResolveTransientStyle(aElement, aPseudo, type, rules);
+    return servoSet->ResolveTransientStyle(aElement, aPseudo, pseudoType, rules);
   }
 
   RefPtr<nsStyleContext> parentContext;
   nsIContent* parent = aPseudo ? aElement : aElement->GetParent();
   // Don't resolve parent context for document fragments.
   if (parent && parent->IsElement()) {
     parentContext = GetStyleContextNoFlush(parent->AsElement(), nullptr,
                                            aPresShell, aStyleType);
   }
 
   StyleResolver styleResolver(presContext, aAnimationFlag);
 
   if (aAnimationFlag == eWithAnimation) {
     return styleResolver.ResolveWithAnimation(styleSet,
-                                              aElement, type,
+                                              aElement, pseudoType,
                                               parentContext,
                                               aStyleType,
                                               inDocWithShell);
   }
 
   return styleResolver.ResolveWithoutAnimation(styleSet,
-                                               aElement, type,
+                                               aElement, pseudoType,
                                                parentContext,
                                                inDocWithShell);
 }
 
 nsMargin
 nsComputedDOMStyle::GetAdjustedValuesForBoxSizing()
 {
   // We want the width/height of whatever parts 'width' or 'height' controls,