Add initial/inherit/unset tests to font-family-parse-keyword.html

Source/core/css/parser/CSSPropertyParser.cpp

Index: Source/core/css/parser/CSSPropertyParser.cpp
diff --git a/Source/core/css/parser/CSSPropertyParser.cpp b/Source/core/css/parser/CSSPropertyParser.cpp
index 6dd294d5b18655ba75c3e2d3ff776487f844e9a3..bab489e49c1e5419fbaef90f6ce1431e0151ad6d 100644
--- a/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/Source/core/css/parser/CSSPropertyParser.cpp
@@ -3198,7 +3198,7 @@ PassRefPtrWillBeRawPtr<CSSValueList> CSSPropertyParser::parseAnimationPropertyLi
 
 static inline bool isCSSWideKeyword(CSSParserValue& value)
 {
-    return value.id == CSSValueInitial || value.id == CSSValueInherit || value.id == CSSValueDefault;
+    return value.id == CSSValueInitial || value.id == CSSValueInherit || value.id == CSSValueUnset || value.id == CSSValueDefault;
 }
 
 static inline bool isValidCustomIdentForGridPositions(CSSParserValue& value)