Add workaround 'fDisallowDirectRG8ReadPixels' for Radeon Pro 5000 GPUs.

The Radeon Pro 5000 series appears to be affected by the same RG8 bug as
the Radeon R9 M300 and Radeon Pro Vega GPUs. This workaround resolves a
DM failure in TransferPixelsTest.

Bug: skia:10256
Change-Id: Ic80aecdba7e2973ddcec78b1c8b665be219249e9
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/291048
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
1 file changed