[CSS Grid Layout] Update named grid lines syntax to the last version of the specs

Source/core/css/CSSParserValues.cpp

Index: Source/core/css/CSSParserValues.cpp
diff --git a/Source/core/css/CSSParserValues.cpp b/Source/core/css/CSSParserValues.cpp
index 9863e9a59620bb6e0eaa5fd4502580e4705de4dd..822ee423a3ed7fc042fd434b56370e737bc0e650 100644
--- a/Source/core/css/CSSParserValues.cpp
+++ b/Source/core/css/CSSParserValues.cpp
@@ -36,6 +36,8 @@ CSSParserValueList::~CSSParserValueList()
     for (size_t i = 0; i < numValues; i++) {
         if (m_values[i].unit == CSSParserValue::Function)
             delete m_values[i].function;
+        else if (m_values[i].unit == CSSParserValue::ValueList)
+            delete m_values[i].valueList;
     }
 }
 
@@ -73,6 +75,8 @@ PassRefPtr<CSSValue> CSSParserValue::createCSSValue()
     }
     if (unit == CSSParserValue::Function)
         return CSSFunctionValue::create(function);
+    if (unit == CSSParserValue::ValueList)
+        return CSSValueList::createFromParserValueList(valueList);
     if (unit >= CSSParserValue::Q_EMS)
         return CSSPrimitiveValue::createAllowingMarginQuirk(fValue, CSSPrimitiveValue::CSS_EMS);