[graphite] For now, draw glyphs as paths.

Adds a parameter to SDFTControl that forces all glyphs to fail as SDF
or Direct, and sets it in the Graphite Device constructor.

Bug: skia:13118
Change-Id: I212e35e992bb14925ec66fca610bb0825ff467b8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/550618
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
4 files changed