Revert "Simplify plots to always be 512x512 and simplify GrDrawOpAtlasConfig"

This reverts commit a2bc1ca21bbc354ec6b1d2a3456ef0c367593e8b.

Reason for revert: see if make chromecast failures go away

Original change's description:
> Simplify plots to always be 512x512 and simplify GrDrawOpAtlasConfig
> 
> Change-Id: I1353d3facf191e3323027fc288715672240d1f87
> Reviewed-on: https://skia-review.googlesource.com/152591
> Reviewed-by: Jim Van Verth <jvanverth@google.com>
> Reviewed-by: Herb Derby <herb@google.com>
> Commit-Queue: Herb Derby <herb@google.com>

TBR=jvanverth@google.com,bsalomon@google.com,herb@google.com

Change-Id: I970ec86678c97046001889dc436df5307750da1b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/153180
Reviewed-by: Cary Clark <caryclark@skia.org>
Commit-Queue: Cary Clark <caryclark@skia.org>
8 files changed