remove use of xfermode* in procs

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4592

Change-Id: I99f35924ff5325dfac527bb573a86d2d0366e0b3
Reviewed-on: https://skia-review.googlesource.com/4592
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Mike Reed <reed@google.com>
19 files changed