Move SkSurface creation into TestEffect and TestBlend classes.

This simplifies the code somewhat, but more importantly, it gives us
an easy way to recreate the surface between draws. This will make it
easier to test in Graphite, because repeated calls to `onReadPixels`
currently fail on some machines unless the surface is recreated
after each read.

Change-Id: I25041f50f1bf9ed5c2130d5e0e212d7bf1a40ac0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/583557
Reviewed-by: Greg Daniel <egdaniel@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
1 file changed