Remove use of SkDropShadowImageFilter::ShadowMode internally

This is in preparation of exposing new factory functions DropShadow()
and DropShadowOnly(), which do not take the enum at all in their params.

Bug: skia:9280
Change-Id: If6e16f46e94b54ab156d2fd02c59fd6171a30f2e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/230742
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
1 file changed