Oilpan: avoid invoking some no-op finalizers.

Source/core/css/StyleSheetList.h

Index: Source/core/css/StyleSheetList.h
diff --git a/Source/core/css/StyleSheetList.h b/Source/core/css/StyleSheetList.h
index a34b0808ab4974f4d39488f232dd6fd019964f7b..d4dfa9799069f102e61e783f9688cbd3ccbed4fc 100644
--- a/Source/core/css/StyleSheetList.h
+++ b/Source/core/css/StyleSheetList.h
@@ -34,11 +34,11 @@ namespace blink {
 class HTMLStyleElement;
 class StyleSheet;
 
-class StyleSheetList : public RefCountedWillBeGarbageCollectedFinalized<StyleSheetList>, public ScriptWrappable {
+class StyleSheetList final : public RefCountedWillBeGarbageCollected<StyleSheetList>, public ScriptWrappable {
+    DECLARE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(StyleSheetList);
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PassRefPtrWillBeRawPtr<StyleSheetList> create(TreeScope* treeScope) { return adoptRefWillBeNoop(new StyleSheetList(treeScope)); }
-    ~StyleSheetList();
 
     unsigned length();
     StyleSheet* item(unsigned index);
@@ -56,7 +56,7 @@ public:
     void trace(Visitor*);
 
 private:
-    StyleSheetList(TreeScope*);
+    explicit StyleSheetList(TreeScope*);
     const WillBeHeapVector<RefPtrWillBeMember<StyleSheet> >& styleSheets();
 
     RawPtrWillBeMember<TreeScope> m_treeScope;