--- a/layout/style/ServoStyleSet.cpp
+++ b/layout/style/ServoStyleSet.cpp
@@ -766,23 +766,16 @@ ServoStyleSet::InsertStyleSheetBefore(Sh
     Servo_StyleSet_InsertStyleSheetBefore(
         mRawSet.get(), aNewSheet, aReferenceSheet);
     SetStylistStyleSheetsDirty();
   }
 
   return NS_OK;
 }
 
-void
-ServoStyleSet::UpdateStyleSheet(ServoStyleSheet* aSheet)
-{
-  MOZ_ASSERT(aSheet);
-  // TODO(emilio): Get rid of this.
-}
-
 int32_t
 ServoStyleSet::SheetCount(SheetType aType) const
 {
   MOZ_ASSERT(nsStyleSet::IsCSSSheetType(aType));
   return mSheets[aType].Length();
 }
 
 ServoStyleSheet*

--- a/layout/style/ServoStyleSet.h
+++ b/layout/style/ServoStyleSet.h
@@ -233,21 +233,16 @@ public:
   nsresult PrependStyleSheet(SheetType aType, ServoStyleSheet* aSheet);
   nsresult RemoveStyleSheet(SheetType aType, ServoStyleSheet* aSheet);
   nsresult ReplaceSheets(SheetType aType,
                          const nsTArray<RefPtr<ServoStyleSheet>>& aNewSheets);
   nsresult InsertStyleSheetBefore(SheetType aType,
                                   ServoStyleSheet* aNewSheet,
                                   ServoStyleSheet* aReferenceSheet);
 
-  // Notify servo that the underlying raw sheet has changed, through cloning.
-  // This should only be called on a just-cloned sheet, because it does not
-  // mark the stylesheets as dirty either here or in servo.
-  void UpdateStyleSheet(ServoStyleSheet* aSheet);
-
   int32_t SheetCount(SheetType aType) const;
   ServoStyleSheet* StyleSheetAt(SheetType aType, int32_t aIndex) const;
 
   void AppendAllXBLStyleSheets(nsTArray<StyleSheet*>& aArray) const;
 
   template<typename Func>
   void EnumerateStyleSheetArrays(Func aCallback) const {
     for (const auto& sheetArray : mSheets) {