Remove all members in ScopedStyleTree for preparing class removal

Source/core/dom/ShadowTreeStyleSheetCollection.cpp

Index: Source/core/dom/ShadowTreeStyleSheetCollection.cpp
diff --git a/Source/core/dom/ShadowTreeStyleSheetCollection.cpp b/Source/core/dom/ShadowTreeStyleSheetCollection.cpp
index 109868b8450053d146af0fd20e8f684a59ac1bfd..8145e4537251aa09e4717a2048925ff7e2c20dcf 100644
--- a/Source/core/dom/ShadowTreeStyleSheetCollection.cpp
+++ b/Source/core/dom/ShadowTreeStyleSheetCollection.cpp
@@ -99,7 +99,7 @@ void ShadowTreeStyleSheetCollection::updateActiveStyleSheets(StyleEngine* engine
         if (change.styleResolverUpdateType != Additive) {
             // We should not destroy StyleResolver when we find any stylesheet update in a shadow tree.
             // In this case, we will reset rulesets created from style elements in the shadow tree.
-            styleResolver->resetAuthorStyle(&m_treeScope.rootNode());
+            styleResolver->resetAuthorStyle(m_treeScope);
             styleResolver->removePendingAuthorStyleSheets(m_activeAuthorStyleSheets);
             styleResolver->lazyAppendAuthorStyleSheets(0, collection.activeAuthorStyleSheets());
         } else {