Revert "move subrun instances and support to .cpp"

This reverts commit 52991f8c81aacc5a7e38daedcfe6744c8b8e5c1e.

Reason for revert: b/172455654

Original change's description:
> move subrun instances and support to .cpp
>
> Change-Id: I12b5110b378a53f0ae416ede5ff864af116a3166
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/331457
> Commit-Queue: Herb Derby <herb@google.com>
> Reviewed-by: Robert Phillips <robertphillips@google.com>

TBR=herb@google.com,robertphillips@google.com

Change-Id: I37bf6785aa0d9609b6a2dc88b409f546cbc95a17
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/332542
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Auto-Submit: Derek Sollenberger <djsollen@google.com>
2 files changed