gm: delete boilerplate

Change-Id: I1fdcbadf8ec587637edfca29cd34f845a11ef045
Reviewed-on: https://skia-review.googlesource.com/c/186083
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Hal Canary <halcanary@google.com>
4 files changed