These are only ever used with the defaults, except in our own tests. A search
of cs.github.com shows no other callers.
The use in the test was solely to bug out the go-metrics package so its
goroutines don't trigger the leak checker. Use the package's own flag for that
purpose instead. Note that calling "Stop" on the metric helps, but is not
sufficient -- the Stop does not wait for its goroutine to exit.