Fix final-dtor-non-final-class warning on GrDDLContext

At some point it became a warning in clang to mark a destructor as final
on a non-final class since it effectively makes the class final.

Change-Id: I1998ac5dbb869011b2633bdfd0e7c8e5fa221877
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/257036
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
1 file changed