[CSS Grid Layout] Update grid-auto-flow to the new syntax

Source/core/css/parser/BisonCSSParser-in.cpp

Index: Source/core/css/parser/BisonCSSParser-in.cpp
diff --git a/Source/core/css/parser/BisonCSSParser-in.cpp b/Source/core/css/parser/BisonCSSParser-in.cpp
index 35e28e2d20afad68e7c5e15d0494f56efdae9528..7ffd7a5cca3219cd4c7aefd07a8dec8a95327a66 100644
--- a/Source/core/css/parser/BisonCSSParser-in.cpp
+++ b/Source/core/css/parser/BisonCSSParser-in.cpp
@@ -525,9 +525,6 @@ bool isValidKeywordPropertyAndValue(CSSPropertyID propertyId, CSSValueID valueID
         return valueID == CSSValueAuto || valueID == CSSValueNormal || valueID == CSSValueNone;
     case CSSPropertyWebkitFontSmoothing:
         return valueID == CSSValueAuto || valueID == CSSValueNone || valueID == CSSValueAntialiased || valueID == CSSValueSubpixelAntialiased;
-    case CSSPropertyGridAutoFlow:
-        return RuntimeEnabledFeatures::cssGridLayoutEnabled()
-            && (valueID == CSSValueNone || valueID == CSSValueRow || valueID == CSSValueColumn);
     case CSSPropertyWebkitLineBreak: // auto | loose | normal | strict | after-white-space
         return valueID == CSSValueAuto || valueID == CSSValueLoose || valueID == CSSValueNormal || valueID == CSSValueStrict || valueID == CSSValueAfterWhiteSpace;
     case CSSPropertyWebkitMarginAfterCollapse:
@@ -656,7 +653,6 @@ bool isKeywordPropertyID(CSSPropertyID propertyId)
     case CSSPropertyJustifyContent:
     case CSSPropertyFontKerning:
     case CSSPropertyWebkitFontSmoothing:
-    case CSSPropertyGridAutoFlow:
     case CSSPropertyWebkitLineBreak:
     case CSSPropertyWebkitMarginAfterCollapse:
     case CSSPropertyWebkitMarginBeforeCollapse: