Refactor compute-convexity

- making it accessible to builders, raw, pathdata, etc.

Change-Id: I28208041f74099d0714f3159e2558ea720767df5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1049116
Reviewed-by: Kaylee Lubick <kjlubick@google.com>
Commit-Queue: Mike Reed <mike@reedtribe.org>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
2 files changed