Revert "Revert "Added SkSL workaround for devices which cannot safely access gl_FragCoord""

This reverts commit 9d6929cccfc3e64e75e6ef5b37f284b01b68fb28.

Reason for revert: Re-landing, backfill reveals none of the red was related to this CL.

Original change's description:
> Revert "Added SkSL workaround for devices which cannot safely access gl_FragCoord"
> 
> This reverts commit 1001f843a45e95f6df1d44242b6b06c77898e870.
> 
> Reason for revert: Many failures.
> 
> Original change's description:
> > Added SkSL workaround for devices which cannot safely access gl_FragCoord
> > 
> > This is the root cause of https://github.com/flutter/flutter/issues/13216
> > I've got a GM that demonstrates the bug, but only in Viewer.
> > 
> > Bug: skia:7410
> > Change-Id: Iaa1f27b10166aa09e4dc5949e5a6ca1bd14c99ac
> > Reviewed-on: https://skia-review.googlesource.com/93920
> > Reviewed-by: Brian Salomon <bsalomon@google.com>
> > Commit-Queue: Brian Osman <brianosman@google.com>
> 
> TBR=bsalomon@google.com,brianosman@google.com,ethannicholas@google.com
> 
> Change-Id: I2a2edc0a8fa11fe9dac1045dc79ae91106518b02
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: skia:7410
> Reviewed-on: https://skia-review.googlesource.com/94281
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Brian Osman <brianosman@google.com>

TBR=bsalomon@google.com,brianosman@google.com,ethannicholas@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: skia:7410
Change-Id: Ib22bda7ff25bb7c8630cc6fa6dc809bf628ea853
Reviewed-on: https://skia-review.googlesource.com/94800
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
6 files changed