Simplify tree scope tracking 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 38 matching lines @@
 
 class StyleEngine final : public CSSFontSelectorClient  {
     WTF_MAKE_FAST_ALLOCATED;
 public:
     static PassOwnPtr<StyleEngine> create(Document& document) { return adoptPtr(new StyleEngine(document)); }
 
     ~StyleEngine();
 
     void detachFromDocument();
 
-    void addStyleSheetCandidateNode(Node*, bool createdByParser);
-    void removeStyleSheetCandidateNode(Node*, ContainerNode* scopingNode, TreeScope&);
+    void addTreeScope(TreeScope&);
+    void removeTreeScope(TreeScope&);
 
     void updateActiveStyleSheets();
 
     // FIXME(sky): Remove this and ::first-line.
     bool usesFirstLineRules() const { return false; }
 
     void appendActiveAuthorStyleSheets();
 
     StyleResolver* resolver() const
     {
@@ skipping 42 matching lines @@
 
     RefPtr<CSSFontSelector> m_fontSelector;
 
     HashMap<AtomicString, StyleSheetContents*> m_textToSheetCache;
     HashMap<StyleSheetContents*, AtomicString> m_sheetToTextCache;
 };
 
 }
 
 #endif  // SKY_ENGINE_CORE_DOM_STYLEENGINE_H_