Add tests for constructors of private types.

This turns out to work fine, but we didn't cover it in any test case.

Change-Id: I98c40dc023bc9f0739beeb6e4163cde087a0be99
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/455499
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
2 files changed