Revert of Move GrDrawAtlasBatch to separate file (patchset #1 id:1 of https://codereview.chromium.org/1274013003/ )

Reason for revert:
Build failures

Original issue's description:
> Move GrDrawAtlasBatch to separate file
>
> Committed: https://skia.googlesource.com/skia/+/b091c44c33edbad3466601b29d60bc2eaa4453fa

TBR=joshualitt@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1276173003
4 files changed