remove some memory-based methods, add rc()

Change-Id: I44d6f67dcd3d042127ad20ebdaa332e94f1b0829
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/266216
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
9 files changed