Reland "Multi-threaded strike cache"

This is a reland of a6cd7c0b1f989840efe203979943cbb59d4d131b

Original change's description:
> Multi-threaded strike cache
>
> Allow multiple threads to share the same strike. The old
> system of removing the cache from the linked list is no longer.
> The strikes stay in the list and can be found by other threads.
>
> * Removed strike size verification. There was no way to get the
> locks to work out. The whole point of the change was to have multiple
> threads muting the structure at the same time.
>
> * Strikes are now refed instead of being checked out. Therefore,
> ExclusiveStrikePtr is now just wraps an sk_sp, and should be renamed
> in a future CL.
>
> Change-Id: I832642332a3106e30745f9cdd3156ae72d41fd0b
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/272057
> Reviewed-by: Ben Wagner <bungeman@google.com>
> Commit-Queue: Herb Derby <herb@google.com>

Change-Id: Id02381de93ff82bca58f09e07a457883d57d5565
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/272436
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
5 files changed