Link stylesheets in shadow trees do not belong to document scope.

third_party/WebKit/Source/core/dom/StyleEngine.cpp

 /*
  * 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, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
@@ skipping 63 matching lines @@
     // HTMLTemplateElement's document, because those documents have no frame.
     m_fontSelector = CSSFontSelector::create(&document);
     m_fontSelector->registerForInvalidationCallbacks(this);
   }
   if (document.isInMainFrame())
     m_viewportResolver = ViewportStyleResolver::create(document);
 }
 
 StyleEngine::~StyleEngine() {}
 
-static bool isStyleElement(Node& node) {
-  return isHTMLStyleElement(node) || isSVGStyleElement(node);
-}
-
 inline Document* StyleEngine::master() {
   if (isMaster())
     return m_document;
   HTMLImportsController* import = document().importsController();
   // Document::import() can return null while executing its destructor.
   if (!import)
     return nullptr;
   return import->master();
 }
 
@@ skipping 54 matching lines @@
   m_pendingScriptBlockingStylesheets++;
 
   context.addingPendingSheet(document());
   if (context.addedPendingSheetBeforeBody())
     m_pendingRenderBlockingStylesheets++;
 }
 
 // This method is called whenever a top-level stylesheet has finished loading.
 void StyleEngine::removePendingSheet(Node& styleSheetCandidateNode,
                                      const StyleEngineContext& context) {
-  TreeScope* treeScope = isStyleElement(styleSheetCandidateNode)
-                             ? &styleSheetCandidateNode.treeScope()
-                             : m_document.get();
   if (styleSheetCandidateNode.isConnected())
-    markTreeScopeDirty(*treeScope);
+    markTreeScopeDirty(styleSheetCandidateNode.treeScope());
 
   if (context.addedPendingSheetBeforeBody()) {
     DCHECK_GT(m_pendingRenderBlockingStylesheets, 0);
     m_pendingRenderBlockingStylesheets--;
   }
 
   // Make sure we knew this sheet was pending, and that our count isn't out of
   // sync.
   DCHECK_GT(m_pendingScriptBlockingStylesheets, 0);
 
   m_pendingScriptBlockingStylesheets--;
   if (m_pendingScriptBlockingStylesheets)
     return;
 
   document().didRemoveAllPendingStylesheet();
 }
 
 void StyleEngine::setNeedsActiveStyleUpdate(
     StyleSheet* sheet,
     StyleResolverUpdateMode updateMode) {
   // resolverChanged() is called for inactive non-master documents because
   // import documents are inactive documents. resolverChanged() for imports
   // will call resolverChanged() for the master document and update the active
   // stylesheets including the ones from the import.
   if (!document().isActive() && isMaster())
     return;
 
   if (sheet && document().isActive()) {
     Node* node = sheet->ownerNode();
-    if (node && node->isConnected()) {
-      TreeScope& treeScope =
-          isStyleElement(*node) ? node->treeScope() : *m_document;
-      DCHECK(isStyleElement(*node) || node->treeScope() == m_document);
-      markTreeScopeDirty(treeScope);
-    }
+    if (node && node->isConnected())
+      markTreeScopeDirty(node->treeScope());
   }
 
   resolverChanged(updateMode);
 }
 
 void StyleEngine::addStyleSheetCandidateNode(Node& node) {
   if (!node.isConnected() || document().isDetached())
     return;
 
   DCHECK(!isXSLStyleSheet(node));
   TreeScope& treeScope = node.treeScope();
   TreeScopeStyleSheetCollection* collection =
       ensureStyleSheetCollectionFor(treeScope);
   DCHECK(collection);
   collection->addStyleSheetCandidateNode(node);
 
   markTreeScopeDirty(treeScope);
   if (treeScope != m_document)
     m_activeTreeScopes.add(&treeScope);
 }
 
 void StyleEngine::removeStyleSheetCandidateNode(Node& node) {
   removeStyleSheetCandidateNode(node, *m_document);
 }
 
 void StyleEngine::removeStyleSheetCandidateNode(Node& node,
                                                 TreeScope& treeScope) {
-  DCHECK(isStyleElement(node) || treeScope == m_document);
   DCHECK(!isXSLStyleSheet(node));
 
   TreeScopeStyleSheetCollection* collection =
       styleSheetCollectionFor(treeScope);
   // After detaching document, collection could be null. In the case,
   // we should not update anything. Instead, just return.
   if (!collection)
     return;
   collection->removeStyleSheetCandidateNode(node);
 
   markTreeScopeDirty(treeScope);
 }
 
 void StyleEngine::modifiedStyleSheetCandidateNode(Node& node) {
   if (!node.isConnected())
     return;
 
-  TreeScope& treeScope = isStyleElement(node) ? node.treeScope() : *m_document;
-  DCHECK(isStyleElement(node) || treeScope == m_document);
-  markTreeScopeDirty(treeScope);
+  markTreeScopeDirty(node.treeScope());
   resolverChanged(AnalyzedStyleUpdate);
 }
 
 void StyleEngine::watchedSelectorsChanged() {
   m_globalRuleSet.initWatchedSelectorsRuleSet(document());
   // TODO(rune@opera.com): Should be able to use RuleSetInvalidation here.
   document().setNeedsStyleRecalc(SubtreeStyleChange,
                                  StyleChangeReasonForTracing::create(
                                      StyleChangeReason::DeclarativeContent));
 }
@@ skipping 794 matching lines @@
 }
 
 DEFINE_TRACE_WRAPPERS(StyleEngine) {
   for (auto sheet : m_injectedAuthorStyleSheets) {
     visitor->traceWrappers(sheet);
   }
   visitor->traceWrappers(m_documentStyleSheetCollection);
 }
 
 }  // namespace blink