add simpler constructor for SkFont

Bug: skia:
Change-Id: I344574cfbba05f013c8844d1a33d680094506ad2
Reviewed-on: https://skia-review.googlesource.com/c/177079
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
2 files changed