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

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

Index: third_party/WebKit/Source/core/css/CSSSelectorList.cpp
diff --git a/third_party/WebKit/Source/core/css/CSSSelectorList.cpp b/third_party/WebKit/Source/core/css/CSSSelectorList.cpp
index 114fb8460e58dd0739288b723d1235976e1d1985..758fffd69689371154c112b5c3b990337855dc1d 100644
--- a/third_party/WebKit/Source/core/css/CSSSelectorList.cpp
+++ b/third_party/WebKit/Source/core/css/CSSSelectorList.cpp
@@ -168,6 +168,13 @@ bool CSSSelectorList::selectorHasShadowDistributed(size_t index) const
     }, selectorAt(index));
 }
 
+bool CSSSelectorList::selectorHasShadowSlotted(size_t index) const
+{
+    return forEachTagSelector([](const CSSSelector& selector) ->  bool {
+        return selector.relationIsAffectedByPseudoSlotted();
+    }, selectorAt(index));
+}
+
 bool CSSSelectorList::selectorUsesDeepCombinatorOrShadowPseudo(size_t index) const
 {
     return forEachTagSelector([](const CSSSelector& selector) -> bool {
@@ -178,7 +185,7 @@ bool CSSSelectorList::selectorUsesDeepCombinatorOrShadowPseudo(size_t index) con
 bool CSSSelectorList::selectorNeedsUpdatedDistribution(size_t index) const
 {
     return forEachTagSelector([](const CSSSelector& selector) -> bool {
-        return selector.relationIsAffectedByPseudoContent() || selector.pseudoType() == CSSSelector::PseudoHostContext;
+        return selector.relationIsAffectedByPseudoContent() || selector.relationIsAffectedByPseudoSlotted() || selector.pseudoType() == CSSSelector::PseudoHostContext;
     }, selectorAt(index));
 }