Remove unused parameter from makeAtlasTextOp

The SubRunOwner parameter was used exclusively for the
*NoCache SubRun system. This system has been removed from
the code.

Change-Id: Ic3b4a1e4f49dcbd9b297e5011d2e96dd163a9acb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/536437
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
3 files changed