Add Config and Cache as params rather than documenting that the caller
has to set them manually.
Change-Id: I8d530be695a0c94bcc4211b496d6e57ec2fff029
Reviewed-on: https://go-review.googlesource.com/c/go/+/526515
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@google.com>