Show mirror drawn with SkStroke (toy stroker)

Improves the sample slide to draw the skeleton geometry, and a mirror
image of the current path with Skia's stroker, which makes it easier to
compare.

Change-Id: I804f4304aec6025112c8ccac3bb61139559022f5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/305184
Reviewed-by: Tyler Denniston <tdenniston@google.com>
Commit-Queue: Tyler Denniston <tdenniston@google.com>
1 file changed