remove cruft bools from canvas

Change-Id: Ic035e2ba24a9c1f8b5b9af56471c130c9efc158c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/263562
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
4 files changed