Add color space xform support to GrDisplacementEffect

BUG=skia:

Change-Id: I7508f27d4da6cec7acb801aa389f70c30cb5bfb5
Reviewed-on: https://skia-review.googlesource.com/6340
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed