Fix GPU sRGB mode in viewer

Need to attach the sRGB color space to the surface to get past validation.

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3905

Change-Id: Icce1c8cf35c31023c116cbcddf8848c4c92cd212
Reviewed-on: https://skia-review.googlesource.com/3905
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed