Reland "Revert "GrDisplacementEffect uses GrTextureEffect.""

This reverts commit 16abfa5e42d162a243950897657cd615d7799de2.

Reason for revert: Appears to have made ANGLE and ios unhappy

Original change's description:
> Revert "Revert "GrDisplacementEffect uses GrTextureEffect.""
> 
> Also further limits the number of FP stages on ANGLE D3D9 to avoid
> varying limit.
> 
> This reverts commit 0b406736c1d09769f1b3fe235b8daa4cd8141ce8.
> 
> Bug: skia:10139
> 
> Change-Id: Ifda0b932ab8ce176f1a1cd1ca9c2deaf1fda20bd
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/284048
> Reviewed-by: Michael Ludwig <michaelludwig@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>

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

Change-Id: I0e4b135a59f713342bf5c6c258779975762ccd1f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:10139
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/284217
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
2 files changed