Current work-in-progress crbug.com/567021

third_party/WebKit/Source/core/css/StyleSheetContents.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2012 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 256 matching lines @@
     }
 
     if (rule->isNamespaceRule())
         return false;
 
     index -= m_namespaceRules.size();
 
     if (rule->isMediaRule())
         setHasMediaQueries();
     else if (rule->isFontFaceRule())
-        setHasFontFaceRule(true);
+        setHasFontFaceRule();
+    else if (rule->isViewportRule())
+        setHasViewportRule();
 
     m_childRules.insert(index, rule);
     return true;
 }
 
 bool StyleSheetContents::wrapperDeleteRule(unsigned index)
 {
     ASSERT(m_isMutable);
     ASSERT_WITH_SECURITY_IMPLICATION(index < ruleCount());
 
@@ skipping 313 matching lines @@
 
 RuleSet& StyleSheetContents::ensureRuleSet(const MediaQueryEvaluator& medium, AddRuleFlags addRuleFlags)
 {
     if (!m_ruleSet) {
         m_ruleSet = RuleSet::create();
         m_ruleSet->addRulesFromSheet(this, medium, addRuleFlags);
     }
     return *m_ruleSet.get();
 }
 
-static void clearResolvers(HeapHashSet<WeakMember<CSSStyleSheet>>& clients)
+RuleSet& StyleSheetContents::ensureEmptyRuleSet()
+{
+    DCHECK(m_ruleSet);
+    m_ruleSet = RuleSet::create();
+    return *m_ruleSet.get();
+}
+
+static void setNeedsActiveStyleUpdateForClients(HeapHashSet<WeakMember<CSSStyleSheet>>& clients)
 {
     for (const auto& sheet : clients) {
-        if (Document* document = sheet->ownerDocument())
-            document->styleEngine().clearResolver();
+        Document* document = sheet->ownerDocument();
+        Node* node = sheet->ownerNode();
+        if (!document || !node || !node->inShadowIncludingDocument())
+            continue;
+        document->styleEngine().setNeedsActiveStyleUpdate(node->treeScope());
     }
 }
 
 void StyleSheetContents::clearRuleSet()
 {
     if (StyleSheetContents* parentSheet = parentStyleSheet())
         parentSheet->clearRuleSet();
 
-    // Don't want to clear the StyleResolver if the RuleSet hasn't been created
-    // since we only clear the StyleResolver so that it's members are properly
-    // updated in ScopedStyleResolver::addRulesFromSheet.
     if (!m_ruleSet)
         return;
 
-    // Clearing the ruleSet means we need to recreate the styleResolver data structures.
-    // See the StyleResolver calls in ScopedStyleResolver::addRulesFromSheet.
-    clearResolvers(m_loadingClients);
-    clearResolvers(m_completedClients);
     m_ruleSet.clear();
+
+    setNeedsActiveStyleUpdateForClients(m_loadingClients);
+    setNeedsActiveStyleUpdateForClients(m_completedClients);
 }
 
 static void removeFontFaceRules(HeapHashSet<WeakMember<CSSStyleSheet>>& clients, const StyleRuleFontFace* fontFaceRule)
 {
     for (const auto& sheet : clients) {
         if (Node* ownerNode = sheet->ownerNode())
             ownerNode->document().styleEngine().removeFontFaceRules(HeapVector<Member<const StyleRuleFontFace>>(1, fontFaceRule));
     }
 }
 
@@ skipping 37 matching lines @@
     visitor->trace(m_importRules);
     visitor->trace(m_namespaceRules);
     visitor->trace(m_childRules);
     visitor->trace(m_loadingClients);
     visitor->trace(m_completedClients);
     visitor->trace(m_ruleSet);
     visitor->trace(m_referencedFromResource);
 }
 
 } // namespace blink