put an arena on GrRenderTargetProxy

This is a reland of 5a2de5e72f24d1bfbdc532252be3dcdefa7b75a2

This is part one of two CLs. In this CL, I put a
sk_sp<GrArenas> on GrRenderTargetProxy where GrArenas wraps
a SkArenaAlloc to add ref counting. Creating
a GrOpsTask shares the GrArenas with the ops task. When an
GrOpsTask is destroyed, it nulls out the fArenas sk_sp on
the GrRenderTargetProxy to limit the life span of the arenas.

New plumbing was added to GR_DRAW_OP_TEST_DEFINE to allow a
proper GrSurfaceDrawContext to be passed to GrAtlasTextOp's
GR_DRAW_OP_TEST_DEFINE so the arena will have a proper lifetime.

The second CL will work on replacing GrOpsTask's fAllocators
system with the shared arena.

Change-Id: Ieb568e4533c17e31b3b015e7781365d7d898c483
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/396818
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Herb Derby <herb@google.com>
13 files changed