Do not compare case-insensitive for 16bit pseudo identifier

Source/core/css/parser/CSSSelectorParser.cpp

Index: Source/core/css/parser/CSSSelectorParser.cpp
diff --git a/Source/core/css/parser/CSSSelectorParser.cpp b/Source/core/css/parser/CSSSelectorParser.cpp
index 17e6a1a54dc839b426bd93208ba797b61df7b6d6..6b50c6e82d7a0b40d70743a3dd3621e51862e33e 100644
--- a/Source/core/css/parser/CSSSelectorParser.cpp
+++ b/Source/core/css/parser/CSSSelectorParser.cpp
@@ -278,7 +278,8 @@ PassOwnPtr<CSSParserSelector> CSSSelectorParser::consumePseudo(CSSParserTokenRan
 
     OwnPtr<CSSParserSelector> selector = CSSParserSelector::create();
     selector->setMatch(colons == 1 ? CSSSelector::PseudoClass : CSSSelector::PseudoElement);
-    selector->setValue(AtomicString(String(token.value()).lower()));
+    String value = token.value();
+    selector->setValue(AtomicString(value.is8Bit() ? value.lower() : value));
 
     if (token.type() == IdentToken) {
         range.consume();