Sample/Shaders: use resources; cleanup code

Change-Id: Icd71734927ebb50c8db55730107deb29faf0c61a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/225716
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
1 file changed