Fix-up colorSpace-less decodes

Follow-up to https://skia-review.googlesource.com/c/skia/+/156627

When attempting to decode into an SkImageInfo without an SkColorSpace,
assume it is SRGB. This updates scanline and incremental decodes to do
so just like getPixels does.

Bug: skia:8382
Change-Id: Ife3c44088be4065c065d7682fe1cb0dc1dd6376f
Reviewed-on: https://skia-review.googlesource.com/c/159325
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>
1 file changed