Don't sort tree scopes in StyleEngine.

sky/engine/core/dom/StyleEngine.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 116 matching lines @@
     virtual void fontsNeedUpdate(CSSFontSelector*) override;
 
 private:
     StyleEngine(Document&);
 
     StyleSheetCollection* ensureStyleSheetCollectionFor(TreeScope&);
     StyleSheetCollection* styleSheetCollectionFor(TreeScope&);
 
     void markTreeScopeDirty(TreeScope&);
 
-    typedef ListHashSet<TreeScope*, 16> TreeScopeSet;
-    static void insertTreeScopeInDocumentOrder(TreeScopeSet&, TreeScope*);
-
     void createResolver();
 
     const StyleSheetCollection* documentStyleSheetCollection() const
     {
         return m_documentStyleSheetCollection.get();
     }
 
     StyleSheetCollection* documentStyleSheetCollection()
     {
         return m_documentStyleSheetCollection.get();
     }
 
     RawPtr<Document> m_document;
 
     // TODO(esprehn): Remove special separate collection for document.
     OwnPtr<StyleSheetCollection> m_documentStyleSheetCollection;
 
     typedef HashMap<RawPtr<TreeScope>, OwnPtr<StyleSheetCollection> > StyleSheetCollectionMap;
     StyleSheetCollectionMap m_styleSheetCollectionMap;
     typedef HashSet<RawPtr<const ScopedStyleResolver> > ScopedStyleResolverSet;
     ScopedStyleResolverSet m_scopedStyleResolvers;
 
+    typedef ListHashSet<TreeScope*, 16> TreeScopeSet;
     TreeScopeSet m_dirtyTreeScopes;
     TreeScopeSet m_activeTreeScopes;
 
     bool m_ignorePendingStylesheets;
     OwnPtr<StyleResolver> m_resolver;
 
     RefPtr<CSSFontSelector> m_fontSelector;
 
     HashMap<AtomicString, RawPtr<StyleSheetContents> > m_textToSheetCache;
     HashMap<RawPtr<StyleSheetContents>, AtomicString> m_sheetToTextCache;
 };
 
 }
 
 #endif  // SKY_ENGINE_CORE_DOM_STYLEENGINE_H_