Remove all members in ScopedStyleTree for preparing class removal

Source/core/css/resolver/StyleResolver.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 125 matching lines @@
     , m_styleSharingDepth(0)
     , m_styleResolverStatsSequence(0)
     , m_accessCount(0)
 {
     FrameView* view = document.view();
     if (view)
         m_medium = adoptPtr(new MediaQueryEvaluator(&view->frame()));
     else
         m_medium = adoptPtr(new MediaQueryEvaluator("all"));
 
-    m_styleTree.ensureScopedStyleResolver(document);
+    m_scopedStyleResolvers.add(&document.ensureScopedStyleResolver());
 
     initWatchedSelectorRules(CSSSelectorWatch::from(document).watchedCallbackSelectors());
 
 #if ENABLE(SVG_FONTS)
     if (document.svgExtensions()) {
         const WillBeHeapHashSet<RawPtrWillBeMember<SVGFontFaceElement> >& svgFontFaceElements = document.svgExtensions()->svgFontFaceElements();
         WillBeHeapHashSet<RawPtrWillBeMember<SVGFontFaceElement> >::const_iterator end = svgFontFaceElements.end();
         for (WillBeHeapHashSet<RawPtrWillBeMember<SVGFontFaceElement> >::const_iterator it = svgFontFaceElements.begin(); it != end; ++it)
             addFontFaceRule(&document, document.styleEngine()->fontSelector(), (*it)->fontFaceRule());
     }
@@ skipping 26 matching lines @@
 {
     ASSERT(cssSheet);
     ASSERT(!cssSheet->disabled());
     if (cssSheet->mediaQueries() && !m_medium->eval(cssSheet->mediaQueries(), &m_viewportDependentMediaQueryResults))
         return;
 
     ContainerNode* scopingNode = ScopedStyleResolver::scopingNodeFor(document(), cssSheet);
     if (!scopingNode)
         return;
 
-    ScopedStyleResolver* resolver = m_styleTree.ensureScopedStyleResolver(*scopingNode);
+    ScopedStyleResolver* resolver = &scopingNode->treeScope().ensureScopedStyleResolver();
+    m_scopedStyleResolvers.add(resolver);
     ASSERT(resolver);
     resolver->addRulesFromSheet(cssSheet, *m_medium, this);
 }
 
 void StyleResolver::appendPendingAuthorStyleSheets()
 {
     for (WillBeHeapListHashSet<RawPtrWillBeMember<CSSStyleSheet>, 16>::iterator it = m_pendingStyleSheets.begin(); it != m_pendingStyleSheets.end(); ++it)
         appendCSSStyleSheet(*it);
 
     m_pendingStyleSheets.clear();
@@ skipping 26 matching lines @@
     // Need to recreate RuleFeatureSet.
     m_features.clear();
     m_siblingRuleSet.clear();
     m_uncommonAttributeRuleSet.clear();
     m_needCollectFeatures = true;
 }
 
 void StyleResolver::processScopedRules(const RuleSet& authorRules, CSSStyleSheet* parentStyleSheet, ContainerNode& scope)
 {
     const WillBeHeapVector<RawPtrWillBeMember<StyleRuleKeyframes> > keyframesRules = authorRules.keyframesRules();
+    ScopedStyleResolver* resolver = &scope.treeScope().ensureScopedStyleResolver();
+    m_scopedStyleResolvers.add(resolver);
     for (unsigned i = 0; i < keyframesRules.size(); ++i)
-        m_styleTree.ensureScopedStyleResolver(scope)->addKeyframeStyle(keyframesRules[i]);
+        resolver->addKeyframeStyle(keyframesRules[i]);
 
     m_treeBoundaryCrossingRules.addTreeBoundaryCrossingRules(authorRules, scope, parentStyleSheet);
 
     // FIXME(BUG 72461): We don't add @font-face rules of scoped style sheets for the moment.
     if (scope.isDocumentNode()) {
         const WillBeHeapVector<RawPtrWillBeMember<StyleRuleFontFace> > fontFaceRules = authorRules.fontFaceRules();
         for (unsigned i = 0; i < fontFaceRules.size(); ++i)
             addFontFaceRule(&m_document, document().styleEngine()->fontSelector(), fontFaceRules[i]);
         if (fontFaceRules.size())
             invalidateMatchedPropertiesCache();
     }
 }
 
-void StyleResolver::resetAuthorStyle(const ContainerNode* scopingNode)
+void StyleResolver::resetAuthorStyle(TreeScope& treeScope)
 {
-    ScopedStyleResolver* resolver = scopingNode ? scopingNode->treeScope().scopedStyleResolver() : m_document.scopedStyleResolver();
+    ScopedStyleResolver* resolver = treeScope.scopedStyleResolver();
     if (!resolver)
         return;
 
-    m_treeBoundaryCrossingRules.reset(scopingNode);
+    m_treeBoundaryCrossingRules.reset(&treeScope.rootNode());
 
     resolver->resetAuthorStyle();
     resetRuleFeatures();
-    if (!scopingNode)
+    if (treeScope.rootNode().isDocumentNode())
         return;
 
-    m_styleTree.remove(scopingNode);
+    // resolver is going to be freed below.
+    m_scopedStyleResolvers.remove(resolver);
+    treeScope.clearScopedStyleResolver();
 }
 
 static PassOwnPtrWillBeRawPtr<RuleSet> makeRuleSet(const WillBeHeapVector<RuleFeature>& rules)
 {
     size_t size = rules.size();
     if (!size)
         return nullptr;
     OwnPtrWillBeRawPtr<RuleSet> ruleSet = RuleSet::create();
     for (size_t i = 0; i < size; ++i)
         ruleSet->addRule(rules[i].rule, rules[i].selectorIndex, rules[i].hasDocumentSecurityOrigin ? RuleHasDocumentSecurityOrigin : RuleHasNoSpecialState);
@@ skipping 14 matching lines @@
         m_features.add(defaultStyleSheets.defaultViewSourceStyle()->features());
 
     if (document().isTransitionDocument())
         m_features.add(defaultStyleSheets.defaultTransitionStyle()->features());
 
     if (m_watchedSelectorsRules)
         m_features.add(m_watchedSelectorsRules->features());
 
     m_treeBoundaryCrossingRules.collectFeaturesTo(m_features);
 
-    m_styleTree.collectFeaturesTo(m_features);
+    HashSet<const StyleSheetContents*> visitedSharedStyleSheetContents;
+    for (WillBeHeapHashSet<RawPtrWillBeMember<const ScopedStyleResolver> >::iterator it = m_scopedStyleResolvers.begin(); it != m_scopedStyleResolvers.end(); ++it)
+        (*it)->collectFeaturesTo(m_features, visitedSharedStyleSheetContents);
 
     m_siblingRuleSet = makeRuleSet(m_features.siblingRules);
     m_uncommonAttributeRuleSet = makeRuleSet(m_features.uncommonAttributeRules);
     m_needCollectFeatures = false;
 }
 
 bool StyleResolver::hasRulesForId(const AtomicString& id) const
 {
     return m_features.hasSelectorForId(id);
 }
@@ skipping 34 matching lines @@
     const ContainerNode* parentsParent = parent.parentOrShadowHostElement();
 
     // We are not always invoked consistently. For example, script execution can cause us to enter
     // style recalc in the middle of tree building. We may also be invoked from somewhere within the tree.
     // Reset the stack in this case, or if we see a new root element.
     // Otherwise just push the new parent.
     if (!parentsParent || m_selectorFilter.parentStackIsEmpty())
         m_selectorFilter.setupParentStack(parent);
     else
         m_selectorFilter.pushParent(parent);
-
-    // Note: We mustn't skip ShadowRoot nodes for the scope stack.
-    m_styleTree.pushStyleCache(parent, parent.parentOrShadowHostNode());
 }
 
 void StyleResolver::popParentElement(Element& parent)
 {
     // Note that we may get invoked for some random elements in some wacky cases during style resolve.
     // Pause maintaining the stack in this case.
     if (m_selectorFilter.parentStackIsConsistent(&parent))
         m_selectorFilter.popParent();
-
-    m_styleTree.popStyleCache(parent);
-}
-
-void StyleResolver::pushParentShadowRoot(const ShadowRoot& shadowRoot)
-{
-    ASSERT(shadowRoot.host());
-    m_styleTree.pushStyleCache(shadowRoot, shadowRoot.host());
-}
-
-void StyleResolver::popParentShadowRoot(const ShadowRoot& shadowRoot)
-{
-    ASSERT(shadowRoot.host());
-    m_styleTree.popStyleCache(shadowRoot);
 }
 
 StyleResolver::~StyleResolver()
 {
+#if !ENABLE(OILPAN)
+    for (WillBeHeapHashSet<RawPtrWillBeMember<const ScopedStyleResolver> >::iterator it = m_scopedStyleResolvers.begin(); it != m_scopedStyleResolvers.end(); ++it)
+        const_cast<TreeScope&>((*it)->treeScope()).clearScopedStyleResolver();

[esprehn, 2014/07/25 05:00:59]

This needs to be done for Oilpan builds too, otherwise we have incorrect
ScopedStyleResolvers hanging off TreeScopes. At the very least we'll need to
guard any access to them with a check that the primary StyleResolver is valid.
It won't crash in Oilpan, but it'll give wrong values back.

[tasak, 2014/07/25 06:02:15]

I chatted with kochi-san.  I think, this clean-up should be done in
StyleEngine::clearResolver, because only  StyleEngine can destory StyleResolver.

+#endif
 }
 
 static inline bool applyAuthorStylesOf(const Element* element)
 {
     return element->treeScope().applyAuthorStyles();
 }
 
 void StyleResolver::matchAuthorRulesForShadowHost(Element* element, ElementRuleCollector& collector, bool includeEmptyRules, WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8>& resolvers, WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8>& resolversInShadowTree)
 {
     collector.clearMatchedRules();
@@ skipping 15 matching lines @@
     m_treeBoundaryCrossingRules.collectTreeBoundaryCrossingRules(element, collector, includeEmptyRules);
     collector.sortAndTransferMatchedRules();
 }
 
 void StyleResolver::matchAuthorRules(Element* element, ElementRuleCollector& collector, bool includeEmptyRules)
 {
     collector.clearMatchedRules();
     collector.matchedResult().ranges.lastAuthorRule = collector.matchedResult().matchedProperties.size() - 1;
 
     bool applyAuthorStyles = applyAuthorStylesOf(element);
-    if (m_styleTree.hasOnlyScopedResolverForDocument()) {
+    if (m_scopedStyleResolvers.size() == 1) {
         m_document.scopedStyleResolver()->collectMatchingAuthorRules(collector, includeEmptyRules, applyAuthorStyles, ignoreCascadeScope);
         m_treeBoundaryCrossingRules.collectTreeBoundaryCrossingRules(element, collector, includeEmptyRules);
         collector.sortAndTransferMatchedRules();
         return;
     }
 
     WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8> resolvers;
     m_styleTree.resolveScopedStyles(element, resolvers);
 
     WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8> resolversInShadowTree;
@@ skipping 1133 matching lines @@
     visitor->trace(m_matchedPropertiesCache);
     visitor->trace(m_viewportDependentMediaQueryResults);
     visitor->trace(m_viewportStyleResolver);
     visitor->trace(m_features);
     visitor->trace(m_siblingRuleSet);
     visitor->trace(m_uncommonAttributeRuleSet);
     visitor->trace(m_watchedSelectorsRules);
     visitor->trace(m_treeBoundaryCrossingRules);
     visitor->trace(m_pendingStyleSheets);
     visitor->trace(m_styleTree);
+    visitor->trace(m_scopedStyleResolvers);
 #endif
 }
 
 } // namespace blink