Have CSSParserContext take a Document reference in argument

Source/web/WebDocument.cpp

Index: Source/web/WebDocument.cpp
diff --git a/Source/web/WebDocument.cpp b/Source/web/WebDocument.cpp
index a6d93df59cf3ae75670ca20c5ae805281975d201..05f9a3742c500cfd763dfbd68d18b92c8ab76224 100644
--- a/Source/web/WebDocument.cpp
+++ b/Source/web/WebDocument.cpp
@@ -203,8 +203,8 @@ WebDocumentType WebDocument::doctype() const
 void WebDocument::insertUserStyleSheet(const WebString& sourceCode, UserStyleLevel styleLevel)
 {
     RefPtr<Document> document = unwrap<Document>();
-
-    RefPtr<StyleSheetContents> parsedSheet = StyleSheetContents::create(document.get());
+    ASSERT(document);
+    RefPtr<StyleSheetContents> parsedSheet = StyleSheetContents::create(*document.get());
     parsedSheet->setIsUserStyleSheet(styleLevel == UserStyleUserLevel);
     parsedSheet->parseString(sourceCode);
     if (parsedSheet->isUserStyleSheet())