Add destination color space to AsFPArgs. Eliminates last XFORMTODO.

src/effects/gradients/SkSweepGradient.cpp

Index: src/effects/gradients/SkSweepGradient.cpp
diff --git a/src/effects/gradients/SkSweepGradient.cpp b/src/effects/gradients/SkSweepGradient.cpp
index 31f481607523e27aeefe76116362fda437c5ee7a..8732534746cd3c51f0dbe1b4905a4ba9c080e59e 100644
--- a/src/effects/gradients/SkSweepGradient.cpp
+++ b/src/effects/gradients/SkSweepGradient.cpp
@@ -193,7 +193,8 @@ sk_sp<GrFragmentProcessor> GrSweepGradient::TestCreate(GrProcessorTestData* d) {
                                                        colorCount));
     SkMatrix viewMatrix = GrTest::TestMatrix(d->fRandom);
     sk_sp<GrFragmentProcessor> fp = shader->asFragmentProcessor(SkShader::AsFPArgs(
-        d->fContext, &viewMatrix, NULL, kNone_SkFilterQuality, SkSourceGammaTreatment::kRespect));
+        d->fContext, &viewMatrix, NULL, kNone_SkFilterQuality, nullptr,
+        SkSourceGammaTreatment::kRespect));
     GrAlwaysAssert(fp);
     return fp;
 }