Rename SkGlyphCacheGlobals to SkStrikeCache

Change-Id: I7773c1fff309bf9416f16fe9908191eeba94eb99
Reviewed-on: https://skia-review.googlesource.com/121356
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
5 files changed