Add support for new CSS ::slotted() pseudo element

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

Index: third_party/WebKit/Source/core/css/RuleSet.cpp
diff --git a/third_party/WebKit/Source/core/css/RuleSet.cpp b/third_party/WebKit/Source/core/css/RuleSet.cpp
index b37c2b00c08f55cec747779f571fcb769540bafe..ad26996422cd913afd25733f8a671af774c5d9d3 100644
--- a/third_party/WebKit/Source/core/css/RuleSet.cpp
+++ b/third_party/WebKit/Source/core/css/RuleSet.cpp
@@ -263,6 +263,8 @@ void RuleSet::addChildRules(const WillBeHeapVector<RefPtrWillBeMember<StyleRuleB
                     m_deepCombinatorOrShadowPseudoRules.append(MinimalRuleData(styleRule, selectorIndex, addRuleFlags));
                 } else if (selectorList.selectorHasShadowDistributed(selectorIndex)) {
                     m_shadowDistributedRules.append(MinimalRuleData(styleRule, selectorIndex, addRuleFlags));
+                } else if (selectorList.selectorHasShadowSlotted(selectorIndex)) {
+                    m_shadowSlottedRules.append(MinimalRuleData(styleRule, selectorIndex, addRuleFlags));
                 } else {
                     addRule(styleRule, selectorIndex, addRuleFlags);
                 }
@@ -343,6 +345,7 @@ void RuleSet::compactRules()
     m_keyframesRules.shrinkToFit();
     m_deepCombinatorOrShadowPseudoRules.shrinkToFit();
     m_shadowDistributedRules.shrinkToFit();
+    m_shadowSlottedRules.shrinkToFit();
 }
 
 DEFINE_TRACE(MinimalRuleData)
@@ -384,6 +387,7 @@ DEFINE_TRACE(RuleSet)
     visitor->trace(m_keyframesRules);
     visitor->trace(m_deepCombinatorOrShadowPseudoRules);
     visitor->trace(m_shadowDistributedRules);
+    visitor->trace(m_shadowSlottedRules);
     visitor->trace(m_viewportDependentMediaQueryResults);
     visitor->trace(m_pendingRules);
 #ifndef NDEBUG