[ngatoy] Fix memory leaks

Bug: skia:11837
Change-Id: Icd80503b16776e821ae2a5491b554eea7094cd9a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/419362
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
5 files changed