Revert of Change SkShader;asFragmentProcessor signature to no longer take skpaint\grcolor*

src/gpu/effects/GrDitherEffect.cpp

Index: src/gpu/effects/GrDitherEffect.cpp
diff --git a/src/gpu/effects/GrDitherEffect.cpp b/src/gpu/effects/GrDitherEffect.cpp
index 3cff899ac53a740041a8ae8b3b1fca7078eb5793..19b2994b5ec71d18d274a83c9bcac19f21cb7248 100644
--- a/src/gpu/effects/GrDitherEffect.cpp
+++ b/src/gpu/effects/GrDitherEffect.cpp
@@ -53,7 +53,7 @@
 
 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(DitherEffect);
 
-const GrFragmentProcessor* DitherEffect::TestCreate(GrProcessorTestData*) {
+GrFragmentProcessor* DitherEffect::TestCreate(GrProcessorTestData*) {
     return DitherEffect::Create();
 }