Some tests around surface creation and snapshotting with color space

bench/nanobench.cpp

Index: bench/nanobench.cpp
diff --git a/bench/nanobench.cpp b/bench/nanobench.cpp
index 4ded06180012700ffe00f73af36de3de528e9f74..a2f931e98b1ad6c395edb5db770aab8153aea953 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -471,7 +471,7 @@ static void create_config(const SkCommandLineConfig* config, SkTArray<Config>* c
         CPU_CONFIG(srgb, kRaster_Backend,
                    kN32_SkColorType,  kPremul_SkAlphaType, srgbColorSpace)
         CPU_CONFIG(f16,  kRaster_Backend,
-                   kRGBA_F16_SkColorType, kPremul_SkAlphaType, srgbColorSpace)
+                   kRGBA_F16_SkColorType, kPremul_SkAlphaType, srgbColorSpace->makeLinearGamma())
     }
 
     #undef CPU_CONFIG