Revert "Add pre-Flush callback to GrDrawingManager"

This reverts commit d222ec492f5d0229986f529134d083e589bcc4a9.

Reason for revert: TegraX1 Vulkan bot

Original change's description:
> Add pre-Flush callback to GrDrawingManager
> 
> This will allow internal systems (e.g., fonts & path renderers) to create pre-flush atlases.
> 
> Depends on: https://skia-review.googlesource.com/c/8988/ (Allow GrSurfaceProxy-derived classes to use flags when instantiating)
> 
> Change-Id: I307796595d651cf376838bff1f9e4385c3753547
> Reviewed-on: https://skia-review.googlesource.com/8679
> Commit-Queue: Robert Phillips <robertphillips@google.com>
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> 

TBR=bsalomon@google.com,robertphillips@google.com,csmartdalton@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I852648adc12d2aa58cd09c57d961c340d657776c
Reviewed-on: https://skia-review.googlesource.com/9735
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
13 files changed