srgb conversion needs to be in unpremul

Bug: skia:
Change-Id: Ic7dffb2cb30aae33a6c127ab10ea4282e1360114
Reviewed-on: https://skia-review.googlesource.com/21536
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
3 files changed