Styling option should not override option:checked UA style

Source/core/css/CSSSelector.cpp

Index: Source/core/css/CSSSelector.cpp
diff --git a/Source/core/css/CSSSelector.cpp b/Source/core/css/CSSSelector.cpp
index b8295a09ab8a43dafd5cd53dabbab15e56f914d5..efddc799db874fe2399ed45c6a75fbe24ec5edfb 100644
--- a/Source/core/css/CSSSelector.cpp
+++ b/Source/core/css/CSSSelector.cpp
@@ -258,6 +258,7 @@ PseudoId CSSSelector::pseudoId(PseudoType type)
     case PseudoFullScreenDocument:
     case PseudoFullScreenAncestor:
     case PseudoSpatialNavigationFocus:
+    case PseudoListBox:
         return NOPSEUDO;
     case PseudoNotParsed:
         ASSERT_NOT_REACHED();
@@ -278,6 +279,7 @@ struct NameToPseudoStruct {
 
 // This table should be kept sorted.
 const static NameToPseudoStruct pseudoTypeMap[] = {
+{"-internal-list-box",            CSSSelector::PseudoListBox},
 {"-internal-spatial-navigation-focus", CSSSelector::PseudoSpatialNavigationFocus},
 {"-webkit-any(",                  CSSSelector::PseudoAny},
 {"-webkit-any-link",              CSSSelector::PseudoAnyLink},
@@ -386,7 +388,6 @@ static CSSSelector::PseudoType nameToPseudoType(const AtomicString& name)
     const NameToPseudoStruct* match = std::lower_bound(pseudoTypeMap, pseudoTypeMapEnd, dummyKey, NameToPseudoCompare(name));
     if (match == pseudoTypeMapEnd || match->string != name.string())
         return CSSSelector::PseudoUnknown;
-
     return static_cast<CSSSelector::PseudoType>(match->type);
 }
 
@@ -532,6 +533,7 @@ void CSSSelector::extractPseudoType() const
     case PseudoHostContext:
     case PseudoUnresolved:
     case PseudoSpatialNavigationFocus:
+    case PseudoListBox:
         break;
     case PseudoFirstPage:
     case PseudoLeftPage:
@@ -784,6 +786,7 @@ static bool validateSubSelector(const CSSSelector* selector)
     case CSSSelector::PseudoHostContext:
     case CSSSelector::PseudoNot:
     case CSSSelector::PseudoSpatialNavigationFocus:
+    case CSSSelector::PseudoListBox:
         return true;
     default:
         return false;