Fix case of asyncRescaleAndReadPixelsYUV420 for case where SkSurface is
backed by non-textureable FBO and no scaling/color space conversions is
performed.

Bug: chromium:1040643

Change-Id: I9fe9dc759fc8b2803569afaf874debd05efbfa33
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/266850
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
2 files changed