Add fuzzer for runtime blenders.

This will be hooked up to oss-fuzz in a followup pull request:
http://go/oss-fuzz/pull/11087

Bug: b/40044964
Change-Id: I8ebca919fc0d9e1fd3b086aba488b9c6b81fb1aa
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/763776
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
3 files changed