Shadow fixes to avoid popping.

* Make geometric shadow generation more tolerant of nearly-convex paths.
* Ensure analytic and geometric shadow positions match with large blurs.

Bug: skia:
Change-Id: I8d3ba43b90d1520cb20f89de9f0b13d11a1a08c3
Reviewed-on: https://skia-review.googlesource.com/127045
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
3 files changed