--- a/build/sanitizers/ubsan_signed_overflow_blacklist.txt
+++ b/build/sanitizers/ubsan_signed_overflow_blacklist.txt
@@ -76,21 +76,16 @@ src:*/nsCharTraits.h
 # Code in xpcom/base/CycleCollectedJSContext.cpp
 fun:*CycleCollectedJSContext*ProcessMetastableStateQueue*
 # Code in layout/painting/nsDisplayList.cpp
 fun:*nsDisplayOpacity*ShouldFlattenAway*
 # Code in modules/libpref/Preferences.cpp
 fun:*pref_InitInitialObjects*
 # Code in netwerk/base/nsIOService.cpp
 fun:*nsIOService*GetCachedProtocolHandler*
-# Code in layout/style/nsCSSRuleProcessor.cpp
-fun:*0nsCSSRuleProcessor@@*
-fun:*nsCSSRuleProcessor*ClearSheets*
-fun:*TreeMatchContext*InitAncestors*
-fun:*TreeMatchContext*InitStyleScopes*
 # Code in layout/xul/nsXULPopupManager.cpp
 fun:*nsXULPopupManager*AdjustPopupsOnWindowChange*
 # Code in dom/base/nsDocument.cpp
 fun:*1nsDocument@@*
 # Code in gfx/layers/ipc/CompositorBridgeChild.cpp
 fun:*CompositorBridgeChild*Destroy*
 # Code in gfx/layers/ipc/ImageBridgeChild.cpp
 fun:*ImageBridgeChild*ShutdownStep1*

--- a/build/sanitizers/ubsan_unsigned_overflow_blacklist.txt
+++ b/build/sanitizers/ubsan_unsigned_overflow_blacklist.txt
@@ -83,21 +83,16 @@ src:*/nsCharTraits.h
 # Code in xpcom/base/CycleCollectedJSContext.cpp
 fun:*CycleCollectedJSContext*ProcessMetastableStateQueue*
 # Code in layout/painting/nsDisplayList.cpp
 fun:*nsDisplayOpacity*ShouldFlattenAway*
 # Code in modules/libpref/Preferences.cpp
 fun:*pref_InitInitialObjects*
 # Code in netwerk/base/nsIOService.cpp
 fun:*nsIOService*GetCachedProtocolHandler*
-# Code in layout/style/nsCSSRuleProcessor.cpp
-fun:*0nsCSSRuleProcessor@@*
-fun:*nsCSSRuleProcessor*ClearSheets*
-fun:*TreeMatchContext*InitAncestors*
-fun:*TreeMatchContext*InitStyleScopes*
 # Code in layout/xul/nsXULPopupManager.cpp
 fun:*nsXULPopupManager*AdjustPopupsOnWindowChange*
 # Code in dom/base/nsDocument.cpp
 fun:*1nsDocument@@*
 # Code in gfx/layers/ipc/CompositorBridgeChild.cpp
 fun:*CompositorBridgeChild*Destroy*
 # Code in gfx/layers/ipc/ImageBridgeChild.cpp
 fun:*ImageBridgeChild*ShutdownStep1*

--- a/dom/xbl/nsXBLPrototypeResources.h
+++ b/dom/xbl/nsXBLPrototypeResources.h
@@ -6,17 +6,16 @@
 
 #ifndef nsXBLPrototypeResources_h__
 #define nsXBLPrototypeResources_h__
 
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/StyleSheet.h"
 #include "nsICSSLoaderObserver.h"
 
-class nsCSSRuleProcessor;
 class nsAtom;
 class nsIContent;
 class nsXBLPrototypeBinding;
 class nsXBLResourceLoader;
 struct RawServoAuthorStyles;
 
 namespace mozilla {
 class CSSStyleSheet;

--- a/layout/style/StyleSheetInfo.h
+++ b/layout/style/StyleSheetInfo.h
@@ -9,17 +9,16 @@
 
 #include "mozilla/css/SheetParsingMode.h"
 #include "mozilla/dom/SRIMetadata.h"
 #include "mozilla/net/ReferrerPolicy.h"
 #include "mozilla/CORSMode.h"
 
 #include "nsIURI.h"
 
-class nsCSSRuleProcessor;
 class nsIPrincipal;
 
 namespace mozilla {
 class StyleSheet;
 
 /**
  * Struct for data common to CSSStyleSheetInner and ServoStyleSheet.
  */