Add metal config to tools

Bug: skia:
Change-Id: I84dbd56c17d4856496af4491f340ec560e29c8a6
Reviewed-on: https://skia-review.googlesource.com/23200
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
4 files changed