Replace SkStrikeSpec with SkStrikeSpecStorage

The SkGlyphRunPainterInterface passed a strike cache in,
but it was only ever needed to get Descriptor. Pass a narrower
object in that just handles strike specifications.

glyphCache -> strike in several places

Change-Id: I98dd9e527149177e61ea26eba64b7868765ac64e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/216349
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
9 files changed