Generalize the squircle runtime effect to draw "super rounded rects"

These are rounded rectangles whose corners are superellipses instead
of ovals. This builds on a lot of work done by zakcohen@google.com to
define a consistent, visually appealing shape that can be used
reliably in the Android UI.

Change-Id: I97fde7be870152c9ee776fde53118019d0caa251
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/397416
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
1 file changed