non-linear blending first steps

Code:
  - Add a non-linear blending bit and makeNonlinearBlending()
    to SkColorSpace
  - remove enough F16=linear checks to make it possible to
    create surfaces and encode pngs with nonlinear F16

Testing:
  - add "esrgb" software config to DM, run it
  - add "srgbnl" software config, run it
  - deemphasize importance of "srgb" config on bots
  - update unit tests to reflect relaxed F16 constraints
  - add a new unit test file with _really_ basic tests,
    and a new unit test that's not working yet

Bug: skia:7942

Change-Id: I8ac042bdf9f3d791765393b68fd9256375184d83
Reviewed-on: https://skia-review.googlesource.com/127325
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/gm/dstreadshuffle.cpp b/gm/dstreadshuffle.cpp
index aaef61d63c..c4c19fcd4e 100644
--- a/gm/dstreadshuffle.cpp
+++ b/gm/dstreadshuffle.cpp
@@ -166,6 +166,7 @@ protected:
                                          canvas->imageInfo().refColorSpace());
             }
             surf = SkSurface::MakeRaster(info);
+            SkASSERT(surf);
         }
         canvas->scale(5.f, 5.f);
         canvas->translate(67.f, 10.f);