Convert SkGlyph::toMask() to SkGlyph::mask()

Change-Id: I749fd152281df8942f488010c356ea0af10c5dea
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/207885
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
5 files changed