--- a/layout/base/PresShell.cpp
+++ b/layout/base/PresShell.cpp
@@ -4575,59 +4575,16 @@ nsIPresShell::RestyleForCSSRuleChanges()
   if (!mDidInitialize) {
     // Nothing to do here, since we have no frames yet
     return;
   }
 
   mStyleSet->InvalidateStyleForCSSRuleChanges();
 }
 
-void
-PresShell::RecordStyleSheetChange(StyleSheet* aStyleSheet,
-                                  StyleSheet::ChangeType aChangeType)
-{
-  // too bad we can't check that the update is UPDATE_STYLE
-  NS_ASSERTION(mUpdateCount != 0, "must be in an update");
-
-  mStyleSet->RecordStyleSheetChange(aStyleSheet, aChangeType);
-}
-
-void
-PresShell::StyleSheetAdded(StyleSheet* aStyleSheet,
-                           bool aDocumentSheet)
-{
-  // We only care when enabled sheets are added
-  NS_PRECONDITION(aStyleSheet, "Must have a style sheet!");
-
-  if (aStyleSheet->IsApplicable() && aStyleSheet->HasRules()) {
-    RecordStyleSheetChange(aStyleSheet, StyleSheet::ChangeType::Added);
-  }
-}
-
-void
-PresShell::StyleSheetRemoved(StyleSheet* aStyleSheet,
-                             bool aDocumentSheet)
-{
-  // We only care when enabled sheets are removed
-  NS_PRECONDITION(aStyleSheet, "Must have a style sheet!");
-
-  if (aStyleSheet->IsApplicable() && aStyleSheet->HasRules()) {
-    RecordStyleSheetChange(aStyleSheet, StyleSheet::ChangeType::Removed);
-  }
-}
-
-void
-PresShell::StyleSheetApplicableStateChanged(StyleSheet* aStyleSheet)
-{
-  if (aStyleSheet->HasRules()) {
-    RecordStyleSheetChange(
-        aStyleSheet, StyleSheet::ChangeType::ApplicableStateChanged);
-  }
-}
-
 nsresult
 PresShell::RenderDocument(const nsRect& aRect, uint32_t aFlags,
                           nscolor aBackgroundColor,
                           gfxContext* aThebesContext)
 {
   NS_ENSURE_TRUE(!(aFlags & RENDER_IS_UNTRUSTED), NS_ERROR_NOT_IMPLEMENTED);
 
   nsRootPresContext* rootPresContext = mPresContext->GetRootPresContext();

--- a/layout/base/PresShell.h
+++ b/layout/base/PresShell.h
@@ -284,19 +284,16 @@ public:
 
   // nsIDocumentObserver
   NS_DECL_NSIDOCUMENTOBSERVER_BEGINUPDATE
   NS_DECL_NSIDOCUMENTOBSERVER_ENDUPDATE
   NS_DECL_NSIDOCUMENTOBSERVER_BEGINLOAD
   NS_DECL_NSIDOCUMENTOBSERVER_ENDLOAD
   NS_DECL_NSIDOCUMENTOBSERVER_CONTENTSTATECHANGED
   NS_DECL_NSIDOCUMENTOBSERVER_DOCUMENTSTATESCHANGED
-  NS_DECL_NSIDOCUMENTOBSERVER_STYLESHEETADDED
-  NS_DECL_NSIDOCUMENTOBSERVER_STYLESHEETREMOVED
-  NS_DECL_NSIDOCUMENTOBSERVER_STYLESHEETAPPLICABLESTATECHANGED
 
   // nsIMutationObserver
   NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATACHANGED
   NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTEWILLCHANGE
   NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
   NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
   NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
   NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
@@ -509,18 +506,16 @@ private:
 
 #ifdef DEBUG
   ServoStyleSet* CloneStyleSet(ServoStyleSet* aSet);
   bool VerifyIncrementalReflow();
   bool mInVerifyReflow;
   void ShowEventTargetDebug();
 #endif
 
-  void RecordStyleSheetChange(StyleSheet* aStyleSheet, StyleSheet::ChangeType);
-
   void RemovePreferenceStyles();
 
   // methods for painting a range to an offscreen buffer
 
   // given a display list, clip the items within the list to
   // the range
   nsRect ClipListToRange(nsDisplayListBuilder *aBuilder,
                          nsDisplayList* aList,

--- a/layout/style/ServoStyleSet.h
+++ b/layout/style/ServoStyleSet.h
@@ -10,17 +10,16 @@
 #include "mozilla/AtomArray.h"
 #include "mozilla/EnumeratedArray.h"
 #include "mozilla/EventStates.h"
 #include "mozilla/MediaFeatureChange.h"
 #include "mozilla/PostTraversalTask.h"
 #include "mozilla/ServoBindingTypes.h"
 #include "mozilla/ServoBindings.h"
 #include "mozilla/ServoUtils.h"
-#include "mozilla/StyleSheetInlines.h"
 #include "mozilla/SheetType.h"
 #include "mozilla/UniquePtr.h"
 #include "MainThreadUtils.h"
 #include "nsCSSPseudoElements.h"
 #include "nsCSSAnonBoxes.h"
 #include "nsChangeHint.h"
 #include "nsCoord.h"
 #include "nsAtom.h"
@@ -112,20 +111,16 @@ public:
   void Shutdown();
 
   // Called when a rules in a stylesheet in this set, or a child sheet of that,
   // are mutated from CSSOM.
   void RuleAdded(ServoStyleSheet&, css::Rule&);
   void RuleRemoved(ServoStyleSheet&, css::Rule&);
   void RuleChanged(ServoStyleSheet& aSheet, css::Rule* aRule);
 
-  // All the relevant changes are handled in RuleAdded / RuleRemoved / etc, and
-  // the relevant AppendSheet / RemoveSheet...
-  void RecordStyleSheetChange(ServoStyleSheet*, StyleSheet::ChangeType) {}
-
   // Runs style invalidation due to document state changes.
   void InvalidateStyleForDocumentStateChanges(EventStates aStatesChanged);
 
   void RecordShadowStyleChange(dom::ShadowRoot&);
 
   bool StyleSheetsHaveChanged() const
   {
     return StylistNeedsUpdate();

--- a/layout/style/StyleSetHandle.h
+++ b/layout/style/StyleSetHandle.h
@@ -137,18 +137,16 @@ public:
     inline void AppendAllXBLStyleSheets(nsTArray<StyleSheet*>& aArray) const;
     inline nsresult RemoveDocStyleSheet(StyleSheet* aSheet);
     inline nsresult AddDocStyleSheet(StyleSheet* aSheet, nsIDocument* aDocument);
 
     inline void RuleRemoved(StyleSheet&, css::Rule&);
     inline void RuleAdded(StyleSheet&, css::Rule&);
     inline void RuleChanged(StyleSheet&, css::Rule*);
 
-    // TODO(emilio): Remove in favor of Rule* methods.
-    inline void RecordStyleSheetChange(StyleSheet* aSheet, StyleSheet::ChangeType);
     inline void RecordShadowStyleChange(mozilla::dom::ShadowRoot& aShadowRoot);
     inline bool StyleSheetsHaveChanged() const;
     inline void InvalidateStyleForCSSRuleChanges();
     inline nsRestyleHint MediumFeaturesChanged(mozilla::MediaFeatureChangeReason);
     inline already_AddRefed<ComputedStyle>
     ProbePseudoElementStyle(dom::Element* aParentElement,
                             mozilla::CSSPseudoElementType aType,
                             ComputedStyle* aParentContext);

--- a/layout/style/StyleSetHandleInlines.h
+++ b/layout/style/StyleSetHandleInlines.h
@@ -226,24 +226,16 @@ StyleSetHandle::Ptr::RuleAdded(StyleShee
 void
 StyleSetHandle::Ptr::RuleChanged(StyleSheet& aSheet, css::Rule* aRule)
 {
   FORWARD_CONCRETE(RuleChanged, (*aSheet.AsGecko(), aRule),
                                 (*aSheet.AsServo(), aRule));
 }
 
 void
-StyleSetHandle::Ptr::RecordStyleSheetChange(StyleSheet* aSheet,
-                                            StyleSheet::ChangeType aChangeType)
-{
-  FORWARD_CONCRETE(RecordStyleSheetChange, (aSheet->AsGecko(), aChangeType),
-                                           (aSheet->AsServo(), aChangeType));
-}
-
-void
 StyleSetHandle::Ptr::RecordShadowStyleChange(mozilla::dom::ShadowRoot& aShadowRoot)
 {
   FORWARD(RecordShadowStyleChange, (aShadowRoot));
 }
 
 bool
 StyleSetHandle::Ptr::StyleSheetsHaveChanged() const
 {