Support Float32 output from SkColorSpaceXform

* Adds Float32 support to SkColorSpaceXform
* Changes API to allows clients to ask for F32, updates clients to
  new API
* Adds Sk4f_load4 and Sk4f_store4 to SkNx
* Make use of new xform in SkGr.cpp

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2339233003
CQ_INCLUDE_TRYBOTS=master.client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot

Committed: https://skia.googlesource.com/skia/+/43d6651111374b5d1e4ddd9030dcf079b448ec47
Review-Url: https://codereview.chromium.org/2339233003
diff --git a/tests/ColorSpaceXformTest.cpp b/tests/ColorSpaceXformTest.cpp
index 0beb38f..2401af5 100644
--- a/tests/ColorSpaceXformTest.cpp
+++ b/tests/ColorSpaceXformTest.cpp
@@ -7,6 +7,7 @@
 
 #include "Resources.h"
 #include "SkCodec.h"
+#include "SkCodecPriv.h"
 #include "SkColorPriv.h"
 #include "SkColorSpace.h"
 #include "SkColorSpace_Base.h"
@@ -39,7 +40,8 @@
 
     // Create and perform an identity xform.
     std::unique_ptr<SkColorSpaceXform> xform = ColorSpaceXformTest::CreateIdentityXform(gammas);
-    xform->apply(dstPixels, srcPixels, width, kN32_SkColorType, kOpaque_SkAlphaType);
+    xform->apply(dstPixels, srcPixels, width, select_xform_format(kN32_SkColorType),
+                 kOpaque_SkAlphaType);
 
     // Since the src->dst matrix is the identity, and the gamma curves match,
     // the pixels should be unchanged.