Add SkColorSpaceXform to the public API

bench/ColorCodecBench.cpp

Index: bench/ColorCodecBench.cpp
diff --git a/bench/ColorCodecBench.cpp b/bench/ColorCodecBench.cpp
index b2bb658ffbec49c535a4b2e86a39788d6641057f..3b0ff6706c03fb8c9ae640e85a953e8b84633fab 100644
--- a/bench/ColorCodecBench.cpp
+++ b/bench/ColorCodecBench.cpp
@@ -101,9 +101,9 @@ void ColorCodecBench::xformOnly() {
     void* dst = fDst.get();
     void* src = fSrc.get();
     for (int y = 0; y < fSrcInfo.height(); y++) {
-        xform->apply(dst, (uint32_t*) src, fSrcInfo.width(),
-                     select_xform_format(fDstInfo.colorType()),
-                     SkColorSpaceXform::kRGBA_8888_ColorFormat, fDstInfo.alphaType());
+        SkAssertResult(xform->apply(select_xform_format(fDstInfo.colorType()), dst,
+                                    SkColorSpaceXform::kRGBA_8888_ColorFormat, src,
+                                    fSrcInfo.width(), fDstInfo.alphaType()));
         dst = SkTAddOffset<void>(dst, fDstInfo.minRowBytes());
         src = SkTAddOffset<void>(src, fSrcInfo.minRowBytes());
     }