Revert "Allow GrDrawOpAtlas to grow as needed"

This reverts commit 03168b8a62a0d3d14b7a0d14642df4d82203b87c.

Reason for revert: Assert in resetting texture proxies.

Original change's description:
> Allow GrDrawOpAtlas to grow as needed
> 
> Bug: skia:3550
> Change-Id: Ib5312c8c06ba8549d90545658df6686c45058255
> Reviewed-on: https://skia-review.googlesource.com/45841
> Commit-Queue: Jim Van Verth <jvanverth@google.com>
> Reviewed-by: Robert Phillips <robertphillips@google.com>

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

Change-Id: I05e084b4cefa57e558f296d6087d4f03fa16ac81
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:3550
Reviewed-on: https://skia-review.googlesource.com/47140
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
14 files changed