Add pointer-data fields to PaintParamsKey and KeyBuilder.

The BlockReader does not yet support pointer-data; that will be
implemented in a followup CL.

Change-Id: I01cd3712241071095fdb9cde741b8566d2761926
Bug: skia:13428
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/550179
Commit-Queue: John Stiles <johnstiles@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
6 files changed