Chrome uses a picture to manage some of their drawing in the GPU
process. This CL serializes GrSlugs into an SkPicture, and to
draw from that picture. Pictures with GrSlugs can not be stored;
they must be created and played back directly. In addition, the
SkStrikes used by the slugs must be pinned in the SkStrikeCache.
Bug: chromium:1302036
Change-Id: I19fa9c06c08f64ad066326e90bc6425dd90b3342
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/514360
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
627969bf1b