Add GM to test SkToSRGBColorFilter

Bug: skia:
Change-Id: If342ad5503d1b427f2d04ce15b75f0f7fa2706c1
Reviewed-on: https://skia-review.googlesource.com/26426
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
3 files changed