Simplify tree scope tracking in StyleEngine.

sky/engine/core/html/HTMLStyleElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2010 Apple Inc. All rights reserved.
  *           (C) 2007 Rob Buis (buis@kde.org)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 12 matching lines @@
 
 #include "sky/engine/config.h"
 #include "sky/engine/core/html/HTMLStyleElement.h"
 
 #include "gen/sky/core/HTMLNames.h"
 #include "sky/engine/core/css/MediaList.h"
 #include "sky/engine/core/css/MediaQueryEvaluator.h"
 #include "sky/engine/core/dom/Document.h"
 #include "sky/engine/core/dom/Element.h"
 #include "sky/engine/core/dom/StyleEngine.h"
+#include "sky/engine/core/dom/StyleSheetCollection.h"
 #include "sky/engine/core/dom/shadow/ShadowRoot.h"
 #include "sky/engine/core/frame/LocalFrame.h"
 #include "sky/engine/platform/TraceEvent.h"
 
 namespace blink {
 
 inline HTMLStyleElement::HTMLStyleElement(Document& document)
     : HTMLElement(HTMLNames::styleTag, document)
 {
 }
 
 HTMLStyleElement::~HTMLStyleElement()
 {
     if (m_sheet)
         m_sheet->clearOwnerNode();
-
-    // TODO(esprehn): How can we still be in the document when our destructor
-    // is running?
-    if (inDocument()) {
-        ContainerNode* scopingNode = this->scopingNode();
-        TreeScope& scope = scopingNode ? scopingNode->treeScope() : treeScope();
-        if (StyleEngine* styleEngine = document().styleEngine())
-            styleEngine->removeStyleSheetCandidateNode(this, scopingNode, scope);
-    }
-
     if (m_sheet)
         clearSheet();
 }
 
 PassRefPtr<HTMLStyleElement> HTMLStyleElement::create(Document& document)
 {
     return adoptRef(new HTMLStyleElement(document));
 }
 
 void HTMLStyleElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
 {
     if (name == HTMLNames::mediaAttr && inDocument() && document().isActive() && m_sheet) {
         m_sheet->setMediaQueries(MediaQuerySet::create(value));
         document().modifiedStyleSheet(m_sheet.get());
     } else {
         HTMLElement::parseAttribute(name, value);
     }
 }
 
 void HTMLStyleElement::insertedInto(ContainerNode* insertionPoint)
 {
     HTMLElement::insertedInto(insertionPoint);
-    if (inActiveDocument()) {
-        document().styleEngine()->addStyleSheetCandidateNode(this, false);
-        process();
-    }
+    if (!inActiveDocument())
+        return;
+    treeScope().styleSheets().addStyleSheetCandidateNode(*this);
+    process();
 }
 
 void HTMLStyleElement::removedFrom(ContainerNode* insertionPoint)
 {
     HTMLElement::removedFrom(insertionPoint);
 
     if (!insertionPoint->inActiveDocument())
         return;
 
-    ShadowRoot* scopingNode = containingShadowRoot();
-    if (!scopingNode)
-        scopingNode = insertionPoint->containingShadowRoot();
-
     TreeScope* containingScope = containingShadowRoot();
     TreeScope& scope = containingScope ? *containingScope : insertionPoint->treeScope();
 
-    document().styleEngine()->removeStyleSheetCandidateNode(this, scopingNode, scope);
+    scope.styleSheets().removeStyleSheetCandidateNode(*this);
 
     RefPtr<CSSStyleSheet> removedSheet = m_sheet.get();
 
     if (m_sheet)
         clearSheet();
     if (removedSheet)
         document().removedStyleSheet(removedSheet.get());
 }
 
 void HTMLStyleElement::childrenChanged(const ChildrenChange& change)
@@ skipping 40 matching lines @@
     if (screenEval.eval(mediaQueries.get())) {
         const String& text = textFromChildren();
         m_sheet = document().styleEngine()->createSheet(this, text);
         m_sheet->setMediaQueries(mediaQueries.release());
     }
 
     document().styleResolverChanged();
 }
 
 }