Reland "Prevent masked solid-color draws from being turned into clears"

This reverts commit f92bb3785fa8015cde9f379be52dedfce5abc290.

Reason for revert: The new unit test has been suppressed on ANGLE

Original change's description:
> Revert "Prevent masked solid-color draws from being turned into clears"
> 
> This reverts commit e9f2bbe082e9e1eb9d76e3043adedc9443427d8d.
> 
> Reason for revert: ANGLE
> 
> Original change's description:
> > Prevent masked solid-color draws from being turned into clears
> > 
> > GrRenderTargetContext::drawRect was eliding a BlurMask filtered circle.
> > 
> > Bug: skia:7765
> > Change-Id: Id98c059f7d786ee5c9bca839c8e099997ff2aedb
> > Reviewed-on: https://skia-review.googlesource.com/122793
> > Reviewed-by: Brian Salomon <bsalomon@google.com>
> 
> TBR=bsalomon@google.com,robertphillips@google.com
> 
> Change-Id: I1b7752eab0fcf55ab6248eed587fd85d438efd78
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: skia:7765
> Reviewed-on: https://skia-review.googlesource.com/122960
> Reviewed-by: Robert Phillips <robertphillips@google.com>
> Commit-Queue: Robert Phillips <robertphillips@google.com>

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

Change-Id: If432c24548ef0f6df4fd6a06aa3b1fb38ba793b8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:7765
Reviewed-on: https://skia-review.googlesource.com/123000
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
2 files changed