Reland "[graphite] Remember last snapped task for scratch devices"

This reverts commit 0e3bd4c3f170b41329bb3f86be2b40da7474e3b4.

Reason for revert: fixed definition of isScratchDevice() to not
count lazy proxies as scratch.

Original change's description:
> Revert "[graphite] Remember last snapped task for scratch devices"
>
> This reverts commit bd6746e5de928ae73b288bc56e0b3d0f4197b233.
>
> Reason for revert: breaking backdrop filter tests in chrome
>
> Original change's description:
> > [graphite] Remember last snapped task for scratch devices
> >
> > Change-Id: I3297b584fd48dc7151d4fff54218c1da2bbfcd5a
> > Reviewed-on: https://skia-review.googlesource.com/c/skia/+/835576
> > Commit-Queue: Michael Ludwig <michaelludwig@google.com>
> > Reviewed-by: Robert Phillips <robertphillips@google.com>
>
> Change-Id: I697299e6c7e34355a934d8fc17593d6b3f29ccf8
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/842917
> Auto-Submit: Michael Ludwig <michaelludwig@google.com>
> Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>

Change-Id: Ia2fb364d40d86a6038f68937961420b28d002915
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/842918
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
2 files changed