Remove all members in ScopedStyleTree for preparing class removal

Source/core/dom/DocumentStyleSheetCollection.cpp

Index: Source/core/dom/DocumentStyleSheetCollection.cpp
diff --git a/Source/core/dom/DocumentStyleSheetCollection.cpp b/Source/core/dom/DocumentStyleSheetCollection.cpp
index 70c8c58062e8396e0a6d2cbe3cdb4f5fbfbf88d4..85bce3c8ab1eb2fbcc3bd032a6a5ba54f97da7ae 100644
--- a/Source/core/dom/DocumentStyleSheetCollection.cpp
+++ b/Source/core/dom/DocumentStyleSheetCollection.cpp
@@ -107,7 +107,7 @@ void DocumentStyleSheetCollection::updateActiveStyleSheets(StyleEngine* engine,
     } else if (StyleResolver* styleResolver = engine->resolver()) {
         if (change.styleResolverUpdateType != Additive) {
             ASSERT(change.styleResolverUpdateType == Reset);
-            styleResolver->resetAuthorStyle(&m_treeScope.rootNode());
+            styleResolver->resetAuthorStyle(m_treeScope);
             engine->removeFontFaceRules(change.fontFaceRulesToRemove);
             styleResolver->removePendingAuthorStyleSheets(m_activeAuthorStyleSheets);
             styleResolver->lazyAppendAuthorStyleSheets(0, collection.activeAuthorStyleSheets());