--- a/dom/smil/nsSMILCSSValueType.cpp
+++ b/dom/smil/nsSMILCSSValueType.cpp
@@ -255,18 +255,19 @@ nsSMILCSSValueType::Add(nsSMILValue& aDe
              "Trying to add invalid types");
   MOZ_ASSERT(aValueToAdd.mType == this, "Unexpected source type");
 
   ValueWrapper* destWrapper = ExtractValueWrapper(aDest);
   const ValueWrapper* valueToAddWrapper = ExtractValueWrapper(aValueToAdd);
   MOZ_ASSERT(destWrapper || valueToAddWrapper,
              "need at least one fully-initialized value");
 
-  nsCSSPropertyID property = (valueToAddWrapper ? valueToAddWrapper->mPropID :
-                            destWrapper->mPropID);
+  nsCSSPropertyID property = valueToAddWrapper
+                             ? valueToAddWrapper->mPropID
+                             : destWrapper->mPropID;
   // Special case: font-size-adjust and stroke-dasharray are explicitly
   // non-additive (even though StyleAnimationValue *could* support adding them)
   if (property == eCSSProperty_font_size_adjust ||
       property == eCSSProperty_stroke_dasharray) {
     return NS_ERROR_FAILURE;
   }
 
   const AnimationValue* valueToAdd = valueToAddWrapper