Add parseFontFaceDescriptor for @font-face handling

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 a8d1d666440dcd57a5faf4e17f3ad3dc193b1808..075f8eac1c9a4c7b4078cc8a11b889a21555a4e8 100644
--- a/Source/core/css/parser/BisonCSSParser-in.cpp
+++ b/Source/core/css/parser/BisonCSSParser-in.cpp
@@ -726,19 +726,11 @@ StyleRuleBase* BisonCSSParser::createStyleRule(Vector<OwnPtr<CSSParserSelector>>
 StyleRuleBase* BisonCSSParser::createFontFaceRule()
 {
     m_allowImportRules = m_allowNamespaceDeclarations = false;
-    for (unsigned i = 0; i < m_parsedProperties.size(); ++i) {
-        CSSProperty& property = m_parsedProperties[i];
-        if (property.id() == CSSPropertyFontFamily && (!property.value()->isValueList() || toCSSValueList(property.value())->length() != 1)) {
-            // Unlike font-family property, font-family descriptor in @font-face rule
-            // has to be a value list with exactly one family name. It cannot have a
-            // have 'initial' value and cannot 'inherit' from parent.
-            // See http://dev.w3.org/csswg/css3-fonts/#font-family-desc
-            clearProperties();
-            return 0;
-        }
-    }
     RefPtrWillBeRawPtr<StyleRuleFontFace> rule = StyleRuleFontFace::create();
-    rule->setProperties(createStylePropertySet());
+    if (!rule->setProperties(createStylePropertySet())) {
+        clearProperties();
+        return nullptr;
+    }
     clearProperties();
     StyleRuleFontFace* result = rule.get();
     m_parsedRules.append(rule.release());