Add color space and type conversion support to asyncReadPixels

Change-Id: Ie95d467c0fcff75635e0b28ea0065cf0cbc7107b
Bug: skia:8962
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/213180
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
2 files changed