Tentative: clean up applyAuthorStyles

Source/core/css/ElementRuleCollector.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 100 matching lines @@
     if (!propertySet)
         return;
     m_result.ranges.lastAuthorRule = m_result.matchedProperties.size();
     if (m_result.ranges.firstAuthorRule == -1)
         m_result.ranges.firstAuthorRule = m_result.ranges.lastAuthorRule;
     m_result.addMatchedProperties(propertySet);
     if (!isCacheable)
         m_result.isCacheable = false;
 }
 
-static bool rulesApplicableInCurrentTreeScope(const Element* element, const ContainerNode* scopingNode, bool elementApplyAuthorStyles)
+static bool rulesApplicableInCurrentTreeScope(const Element* element, const ContainerNode* scopingNode)
 {
     TreeScope& treeScope = element->treeScope();
 
     // [skipped, because already checked] a) it's a UA rule
-    // b) element is allowed to apply author rules
-    if (elementApplyAuthorStyles)
-        return true;
+    // [skipped, because already checked] b) element is not in shadow tree
     // c) the rules comes from a scoped style sheet within the same tree scope
     if (!scopingNode || treeScope == scopingNode->treeScope())
         return true;
     // d) the rules comes from a scoped style sheet within an active shadow root whose host is the given element
     if (SelectorChecker::isHostInItsShadowTree(*element, scopingNode))
         return true;
     return false;
 }
 
-void ElementRuleCollector::collectMatchingRules(const MatchRequest& matchRequest, RuleRange& ruleRange, SelectorChecker::ContextFlags contextFlags, CascadeScope cascadeScope, CascadeOrder cascadeOrder)
+void ElementRuleCollector::collectMatchingRules(const MatchRequest& matchRequest, RuleRange& ruleRange, CascadeScope cascadeScope, CascadeOrder cascadeOrder)
 {
     ASSERT(matchRequest.ruleSet);
     ASSERT(m_context.element());
 
+    SelectorChecker::ContextFlags contextFlags = SelectorChecker::DefaultBehavior;
+    if (matchRequest.isInShadowTree)
+        contextFlags = SelectorChecker::ScopeContainsLastMatchedElement;
+
     Element& element = *m_context.element();
     const AtomicString& pseudoId = element.shadowPseudoId();
     if (!pseudoId.isEmpty()) {
         ASSERT(element.isStyledElement());
         collectMatchingRulesForList(matchRequest.ruleSet->shadowPseudoElementRules(pseudoId), contextFlags, ignoreCascadeScope, cascadeOrder, matchRequest, ruleRange);
     }
 
     if (element.isVTTElement())
         collectMatchingRulesForList(matchRequest.ruleSet->cuePseudoRules(), contextFlags, cascadeScope, cascadeOrder, matchRequest, ruleRange);
     // Check whether other types of rules are applicable in the current tree scope. Criteria for this:
     // a) it's a UA rule
-    // b) the tree scope allows author rules
+    // b) the tree scope is not shadow tree
     // c) the rules comes from a scoped style sheet within the same tree scope
     // d) the rules comes from a scoped style sheet within an active shadow root whose host is the given element
     // e) the rules can cross boundaries
-    // b)-e) is checked in rulesApplicableInCurrentTreeScope.
-    if (!m_matchingUARules && !rulesApplicableInCurrentTreeScope(&element, matchRequest.scope, matchRequest.elementApplyAuthorStyles))
+    // c)-e) is checked in rulesApplicableInCurrentTreeScope.
+    if (!m_matchingUARules && matchRequest.isInShadowTree && !rulesApplicableInCurrentTreeScope(&element, matchRequest.scope))
         return;
 
     // We need to collect the rules for id, class, tag, and everything else into a buffer and
     // then sort the buffer.
     if (element.hasID())
         collectMatchingRulesForList(matchRequest.ruleSet->idRules(element.idForStyleResolution()), contextFlags, cascadeScope, cascadeOrder, matchRequest, ruleRange);
     if (element.isStyledElement() && element.hasClass()) {
         for (size_t i = 0; i < element.classNames().size(); ++i)
             collectMatchingRulesForList(matchRequest.ruleSet->classRules(element.classNames()[i]), contextFlags, cascadeScope, cascadeOrder, matchRequest, ruleRange);
     }
@@ skipping 173 matching lines @@
     // information about "scope".
     int firstRuleIndex = -1, lastRuleIndex = -1;
     RuleRange ruleRange(firstRuleIndex, lastRuleIndex);
     // FIXME: Verify whether it's ok to ignore CascadeScope here.
     collectMatchingRules(MatchRequest(ruleSet), ruleRange, SelectorChecker::DefaultBehavior);
 
     return m_matchedRules && !m_matchedRules->isEmpty();
 }
 
 } // namespace blink