Approximate common gamma tables as single values

This should improve performance of gamma conversion in
software (we can use vector math instead of table look
ups).

Additionally this allows us to quickly and easily
identify sRGB-like gammas.

On gpu, identifying sRGB gamma improves performance/memory,
because the hardware may support gamma conversion.

This will help us identify situations where gamma
conversion is not necessary.
Ex: sRGB input -> sRGB display

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1950183006

Review-Url: https://codereview.chromium.org/1950183006

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/ColorSpaceTest.cpp b/tests/ColorSpaceTest.cpp
index 7e818caad0..17332d720d 100644
--- a/tests/ColorSpaceTest.cpp
+++ b/tests/ColorSpaceTest.cpp
@@ -74,7 +74,7 @@ DEF_TEST(ColorSpaceParsePngICCProfile, r) {
     const float red[] = { 0.436066f, 0.222488f, 0.013916f };
     const float green[] = { 0.385147f, 0.716873f, 0.0970764f };
     const float blue[] = { 0.143066f, 0.0606079f, 0.714096f };
-    const float gamma[] = { 0, 0, 0 };  // table-based gamma returns 0 from this its float-getter
+    const float gamma[] = { 2.2f, 2.2f, 2.2f };
     test_space(r, colorSpace, red, green, blue, gamma);
 #endif
 }