Fix issue where SkAutoSTMalloc doesn't default initialize std::unique_ptr.

TBR=jvanverth@google.com

Change-Id: Ifd29f55956f640dfc972490244d5d356bac89759
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/225418
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed