Merge StyleSheet into CSSStyleSheet.

sky/engine/core/dom/shadow/ElementShadow.cpp

Index: sky/engine/core/dom/shadow/ElementShadow.cpp
diff --git a/sky/engine/core/dom/shadow/ElementShadow.cpp b/sky/engine/core/dom/shadow/ElementShadow.cpp
index 805ead131efe17a250557be778e97110ebe3e596..00b8079b99dd570f306e652d7906ae02bd1c9062 100644
--- a/sky/engine/core/dom/shadow/ElementShadow.cpp
+++ b/sky/engine/core/dom/shadow/ElementShadow.cpp
@@ -219,7 +219,7 @@ bool ElementShadow::hasSameStyles(const ElementShadow* other) const
             return false;
 
         for (size_t i = 0; i < list->length(); i++) {
-            if (toCSSStyleSheet(list->item(i))->contents() != toCSSStyleSheet(otherList->item(i))->contents())
+            if (list->item(i)->contents() != otherList->item(i)->contents())
                 return false;
         }
     }