Reland "use a linked list for GrAtlasTextOp geometries"

This is a reland of 82a8130654bc6354cdaee9ce05e5d6118e1c5e33

Original change's description:
> use a linked list for GrAtlasTextOp geometries
>
> Instead of using a GrTBlockList<Geometry> to hold the geometries
> in the op. Allocate them on the RecordTimeAllocator, and
> link them together.
>
> Change-Id: I32af5724e7abeca1ddb6d38b26afbff7919cbc76
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/341725
> Reviewed-by: Robert Phillips <robertphillips@google.com>
> Commit-Queue: Herb Derby <herb@google.com>

Change-Id: I526d8b0b06fca13046c065cbc06f0c0e1103ce11
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/371996
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
3 files changed