bool SkColorSpaceXformSteps::Required()

Lots of code asks this question, and more will soon.
It'll be clearer to call a function that doesn't read
as specific to legacy blitters.

Change-Id: I621014c4dab6de4e6c794ddf8430fcc3b87a8044
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/204417
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
diff --git a/src/shaders/SkShader.cpp b/src/shaders/SkShader.cpp
index 992f3e8..8edeafb 100644
--- a/src/shaders/SkShader.cpp
+++ b/src/shaders/SkShader.cpp
@@ -111,7 +111,7 @@
 SkShaderBase::Context::~Context() {}
 
 bool SkShaderBase::ContextRec::isLegacyCompatible(SkColorSpace* shaderColorSpace) const {
-    return sk_can_use_legacy_blits(shaderColorSpace, fDstColorSpace);
+    return !SkColorSpaceXformSteps::Required(shaderColorSpace, fDstColorSpace);
 }
 
 const SkMatrix& SkShader::getLocalMatrix() const {