Make dstreadshuffle not crash in with --preAbandonGpuContext and look better in 565

BUG=skia:6386

Change-Id: I90578f57ba7076d65e6d8ebe61ec325ebba8e35d
Reviewed-on: https://skia-review.googlesource.com/9828
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed