Avoid reaching for StyleResolver::m_features from StyleBuilder.

Source/core/css/resolver/StyleBuilderCustom.cpp

Index: Source/core/css/resolver/StyleBuilderCustom.cpp
diff --git a/Source/core/css/resolver/StyleBuilderCustom.cpp b/Source/core/css/resolver/StyleBuilderCustom.cpp
index be1dedd23d2826d96aff9fd64696a2762c3eabdd..522f07533ded63a63f8ff75bd7168ea2c9fdd444 100644
--- a/Source/core/css/resolver/StyleBuilderCustom.cpp
+++ b/Source/core/css/resolver/StyleBuilderCustom.cpp
@@ -1114,7 +1114,7 @@ void StyleBuilder::oldApplyProperty(CSSPropertyID id, StyleResolver* styleResolv
                     state.style()->setContent(value.isNull() ? emptyAtom : value.impl(), didSet);
                     didSet = true;
                     // register the fact that the attribute value affects the style
-                    styleResolver->m_features.attrsInRules.add(attr.localName().impl());
+                    state.contentAttrValues().append(attr.localName());
                 } else if (contentValue->isCounter()) {
                     Counter* counterValue = contentValue->getCounterValue();
                     EListStyleType listStyleType = NoneListStyle;