Remove the concept of user stylesheets.

Source/core/testing/Internals.cpp

Index: Source/core/testing/Internals.cpp
diff --git a/Source/core/testing/Internals.cpp b/Source/core/testing/Internals.cpp
index 5cacf1c22cefcf96bf49b194a38d93b2f97319c2..3820cdfe3056c402568217f209b56d9779b20a12 100644
--- a/Source/core/testing/Internals.cpp
+++ b/Source/core/testing/Internals.cpp
@@ -1878,28 +1878,6 @@ void Internals::allowRoundingHacks() const
     TextRun::setAllowsRoundingHacks(true);
 }
 
-void Internals::insertAuthorCSS(Document* document, const String& css) const
-{
-    if (!document)
-        return;
-
-    RefPtr<StyleSheetContents> parsedSheet = StyleSheetContents::create(*document);
-    parsedSheet->setIsUserStyleSheet(false);
-    parsedSheet->parseString(css);
-    document->styleEngine()->addAuthorSheet(parsedSheet);
-}
-
-void Internals::insertUserCSS(Document* document, const String& css) const
-{
-    if (!document)
-        return;
-
-    RefPtr<StyleSheetContents> parsedSheet = StyleSheetContents::create(*document);
-    parsedSheet->setIsUserStyleSheet(true);
-    parsedSheet->parseString(css);
-    document->styleEngine()->addUserSheet(parsedSheet);
-}
-
 String Internals::counterValue(Element* element)
 {
     if (!element)