remove SK_SUPPORT_LEGACY_CLIP_REGIONOPS flag

BUG=skia:

Change-Id: I57871d008d3e630369edcef5473a1f1d1f0c0822
NOTRY=True
Reviewed-on: https://skia-review.googlesource.com/5715
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed