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, 0 insertions, 4 deletions

diff --git a/src/images/SkWebpEncoder.cpp b/src/images/SkWebpEncoder.cpp
index a7809b2fa0..ee13563ea7 100644
--- a/src/images/SkWebpEncoder.cpp
+++ b/src/images/SkWebpEncoder.cpp
@@ -88,10 +88,6 @@ static transform_scanline_proc choose_proc(const SkImageInfo& info,
         case kGray_8_SkColorType:
             return transform_scanline_gray;
         case kRGBA_F16_SkColorType:
-            if (!info.colorSpace() || !info.colorSpace()->gammaIsLinear()) {
-                return nullptr;
-            }
-
             switch (info.alphaType()) {
                 case kOpaque_SkAlphaType:
                 case kUnpremul_SkAlphaType: