Only accept inherit/initial/unset in single value declarations

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 667750ead0a019866b5b317f9e90a9eb207b7d06..762a30db60cc4916187116b2f9a17f211c799334 100644
--- a/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/Source/core/css/parser/CSSPropertyParser.cpp
@@ -446,25 +446,25 @@ bool CSSPropertyParser::parseValue(CSSPropertyID propId, bool important)
 
     CSSValueID id = value->id;
 
-    int num = inShorthand() ? 1 : m_valueList->size();
-
     if (id == CSSValueInherit) {
-        if (num != 1)
+        if (m_valueList->size() != 1)
             return false;
         addExpandedPropertyForValue(propId, cssValuePool().createInheritedValue(), important);
         return true;
     } else if (id == CSSValueInitial) {
-        if (num != 1)
+        if (m_valueList->size() != 1)
             return false;
         addExpandedPropertyForValue(propId, cssValuePool().createExplicitInitialValue(), important);
         return true;
     } else if (id == CSSValueUnset) {
-        if (num != 1)
+        if (m_valueList->size() != 1)
             return false;
         addExpandedPropertyForValue(propId, cssValuePool().createUnsetValue(), important);
         return true;
     }
 
+    int num = inShorthand() ? 1 : m_valueList->size();
+
     if (CSSParserFastPaths::isKeywordPropertyID(propId)) {
         if (!CSSParserFastPaths::isValidKeywordPropertyAndValue(propId, id))
             return false;