GM/Sample to test new gradient interpolation options

Bug: skia:13108
Change-Id: I64aa117aef8a51c916698be37b1135d538be501c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/590998
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2 files changed