Initialize renderability in GrMockOptions

Change-Id: I30a042a41991a47ff1a4e008b88431b4767453dd
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/205496
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed