Introduce SkStrikeCacheInterface

Introduce SkStrikeCacheInterface in order to move from a
template a based interface on SkGlyphRunListPainter to
a class based interface.

Change-Id: Ib15e437420c00f4e11242ac1a4d8a87ee2af9ee1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/197101
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
9 files changed