Current work-in-progress crbug.com/567021

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

 /*
  * Copyright (C) 2006, 2007 Rob Buis
  * Copyright (C) 2008 Apple, Inc. All rights reserved.
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 68 matching lines @@
   if (m_registeredAsCandidate) {
     ShadowRoot* shadowRoot = element.containingShadowRoot();
     if (!shadowRoot)
       shadowRoot = insertionPoint->containingShadowRoot();
 
     document.styleEngine().removeStyleSheetCandidateNode(
         element, shadowRoot ? *toTreeScope(shadowRoot) : toTreeScope(document));
     m_registeredAsCandidate = false;
   }
 
-  StyleSheet* removedSheet = m_sheet.get();
-
-  if (m_sheet)
+  if (m_sheet) {
     clearSheet(element);
-  if (removedSheet)
-    document.styleEngine().setNeedsActiveStyleUpdate(removedSheet,
-                                                     AnalyzedStyleUpdate);
+    if (element.isConnected())
+      document.styleEngine().setNeedsActiveStyleUpdate(element.treeScope());
+  }
 }
 
 StyleElement::ProcessingResult StyleElement::childrenChanged(Element& element) {
   if (m_createdByParser)
     return ProcessingSuccessful;
 
   return process(element);
 }
 
 StyleElement::ProcessingResult StyleElement::finishParsingChildren(
@@ skipping 98 matching lines @@
 
 void StyleElement::startLoadingDynamicSheet(Document& document) {
   document.styleEngine().addPendingSheet(m_styleEngineContext);
 }
 
 DEFINE_TRACE(StyleElement) {
   visitor->trace(m_sheet);
 }
 
 }  // namespace blink