Oilpan: implement StyleRuleList without an extra wrapper.

Source/core/css/resolver/StyleResolver.cpp

Index: Source/core/css/resolver/StyleResolver.cpp
diff --git a/Source/core/css/resolver/StyleResolver.cpp b/Source/core/css/resolver/StyleResolver.cpp
index 67dd9d85671efd1e8f88b1ba9acf54221042bdb0..ecfab18bf9aeb5201b1be9a0db93878ab923a37b 100644
--- a/Source/core/css/resolver/StyleResolver.cpp
+++ b/Source/core/css/resolver/StyleResolver.cpp
@@ -1428,8 +1428,8 @@ void StyleResolver::applyCallbackSelectors(StyleResolverState& state)
     RefPtrWillBeRawPtr<StyleRuleList> rules = collector.matchedStyleRuleList();
     if (!rules)
         return;
-    for (size_t i = 0; i < rules->m_list.size(); i++)
-        state.style()->addCallbackSelector(rules->m_list[i]->selectorList().selectorsText());
+    for (size_t i = 0; i < rules->size(); i++)
+        state.style()->addCallbackSelector(rules->at(i)->selectorList().selectorsText());
 }
 
 CSSPropertyValue::CSSPropertyValue(CSSPropertyID id, const StylePropertySet& propertySet)