Stop traversing up the tree looking for ScopedStyleResolvers.

Source/core/css/resolver/StyleResolver.cpp

Index: Source/core/css/resolver/StyleResolver.cpp
diff --git a/Source/core/css/resolver/StyleResolver.cpp b/Source/core/css/resolver/StyleResolver.cpp
index 28550e67db9a5df2dac7e6b32080e76d7740b332..e34c6a0c7b521208b2f6718a1bb996166becd4c8 100644
--- a/Source/core/css/resolver/StyleResolver.cpp
+++ b/Source/core/css/resolver/StyleResolver.cpp
@@ -374,61 +374,30 @@ StyleResolver::~StyleResolver()
 {
 }
 
-void StyleResolver::matchAuthorRulesForShadowHost(Element* element, ElementRuleCollector& collector, bool includeEmptyRules, WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8>& resolvers, WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8>& resolversInShadowTree)
-{
-    collector.clearMatchedRules();
-    collector.matchedResult().ranges.lastAuthorRule = collector.matchedResult().matchedProperties.size() - 1;
-
-    CascadeScope cascadeScope = 0;
-    CascadeOrder cascadeOrder = 0;
-
-    for (int j = resolversInShadowTree.size() - 1; j >= 0; --j)
-        resolversInShadowTree.at(j)->collectMatchingAuthorRules(collector, includeEmptyRules, cascadeScope, cascadeOrder++);
-
-    if (resolvers.isEmpty() || resolvers.first()->treeScope() != element->treeScope())
-        ++cascadeScope;
-    cascadeOrder += resolvers.size();
-    for (unsigned i = 0; i < resolvers.size(); ++i)
-        resolvers.at(i)->collectMatchingAuthorRules(collector, includeEmptyRules, cascadeScope++, --cascadeOrder);
-
-    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;
 
-    if (document().styleEngine()->hasOnlyScopedResolverForDocument()) {
-        document().scopedStyleResolver()->collectMatchingAuthorRules(collector, includeEmptyRules, ignoreCascadeScope);
-        m_treeBoundaryCrossingRules.collectTreeBoundaryCrossingRules(element, collector, includeEmptyRules);
-        collector.sortAndTransferMatchedRules();
-        return;
-    }
+    CascadeOrder cascadeOrder = 0;
 
-    WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8> resolvers;
-    resolveScopedStyles(element, resolvers);
+    // FIXME: We should track host rules separately right now the SelectorChecker
+    // is doing lots of checking to compensate for entering with rules that
+    // shouldn't match in the :host/:host-context step below.
 
+    // Match :host and :host-context rules.
     WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8> resolversInShadowTree;
     collectScopedResolversForHostedShadowTrees(element, resolversInShadowTree);
-    if (!resolversInShadowTree.isEmpty()) {
-        matchAuthorRulesForShadowHost(element, collector, includeEmptyRules, resolvers, resolversInShadowTree);
-        return;
-    }
-
-    if (resolvers.isEmpty())
-        return;
+    for (int j = resolversInShadowTree.size() - 1; j >= 0; --j)
+        resolversInShadowTree[j]->collectMatchingAuthorRules(collector, includeEmptyRules, ignoreCascadeScope, ++cascadeOrder);
 
-    CascadeScope cascadeScope = 0;
-    CascadeOrder cascadeOrder = resolvers.size();
-    for (unsigned i = 0; i < resolvers.size(); ++i, --cascadeOrder) {
-        ScopedStyleResolver* resolver = resolvers.at(i);
-        // FIXME: Need to clarify how to treat style scoped.
-        resolver->collectMatchingAuthorRules(collector, includeEmptyRules, cascadeScope++, resolver->treeScope() == element->treeScope() && resolver->treeScope().rootNode().isShadowRoot() ? 0 : cascadeOrder);
-    }
+    // Match rules in your own scope (ShadowRoot or Document).
+    if (ScopedStyleResolver* resolver = element->treeScope().scopedStyleResolver())
+        resolver->collectMatchingAuthorRules(collector, includeEmptyRules, ignoreCascadeScope, ++cascadeOrder);
 
+    // Match /deep/, ::shadow and ::content rules.
     m_treeBoundaryCrossingRules.collectTreeBoundaryCrossingRules(element, collector, includeEmptyRules);
+
     collector.sortAndTransferMatchedRules();
 }
 
@@ -999,21 +968,6 @@ bool StyleResolver::applyAnimatedProperties(StyleResolverState& state, const Ele
     return true;
 }
 
-static inline ScopedStyleResolver* scopedResolverFor(const Element* element)
-{
-    for (TreeScope* treeScope = &element->treeScope(); treeScope; treeScope = treeScope->parentTreeScope()) {
-        if (ScopedStyleResolver* scopedStyleResolver = treeScope->scopedStyleResolver())
-            return scopedStyleResolver;
-    }
-    return 0;
-}
-
-void StyleResolver::resolveScopedStyles(const Element* element, WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8>& resolvers)
-{
-    for (ScopedStyleResolver* scopedResolver = scopedResolverFor(element); scopedResolver; scopedResolver = scopedResolver->parent())
-        resolvers.append(scopedResolver);
-}
-
 void StyleResolver::collectScopedResolversForHostedShadowTrees(const Element* element, WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8>& resolvers)
 {
     ElementShadow* shadow = element->shadow();
@@ -1031,16 +985,10 @@ void StyleResolver::collectScopedResolversForHostedShadowTrees(const Element* el
 
 void StyleResolver::styleTreeResolveScopedKeyframesRules(const Element* element, WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8>& resolvers)
 {
-    TreeScope& treeScope = element->treeScope();
-
-    // Add resolvers for shadow roots hosted by the given element.
     collectScopedResolversForHostedShadowTrees(element, resolvers);
 
-    // Add resolvers while walking up DOM tree from the given element.
-    for (ScopedStyleResolver* scopedResolver = scopedResolverFor(element); scopedResolver; scopedResolver = scopedResolver->parent()) {
-        if (scopedResolver->treeScope() == treeScope)
-            resolvers.append(scopedResolver);
-    }
+    if (ScopedStyleResolver* scopedResolver = element->treeScope().scopedStyleResolver())
+        resolvers.append(scopedResolver);
 }
 
 template <StyleResolver::StyleApplicationPass pass>