Bug 1289010 - Correct ErrorType message for File CTOR., r=bz

dom/base/File.cpp

@@ -560,7 +560,7 @@ File::Constructor(const GlobalObject& aGlobal,
                   ErrorResult& aRv)
 {
   if (!nsContentUtils::ThreadsafeIsCallerChrome()) {
-    aRv.Throw(NS_ERROR_FAILURE);
+    aRv.ThrowTypeError<MSG_NOT_SEQUENCE>(NS_LITERAL_STRING("Argument 1 of File.constructor"));
     return nullptr;
   }