Move SkFont over to SkStrikeSpecStorage

Change-Id: I5b4adec40162896aa3f6d36f9c83a1fc3744110c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/215095
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Herb Derby <herb@google.com>
1 file changed