Create fragment processor for performing input color blend with child processor

src/effects/SkColorCubeFilter.cpp

Index: src/effects/SkColorCubeFilter.cpp
diff --git a/src/effects/SkColorCubeFilter.cpp b/src/effects/SkColorCubeFilter.cpp
index c5d4fc5a35d0e910fc4d2bdee8167e4fb1a4a0b4..da5635cf71ded6b35492a48fa2ecf7f401e5539c 100644
--- a/src/effects/SkColorCubeFilter.cpp
+++ b/src/effects/SkColorCubeFilter.cpp
@@ -304,7 +304,7 @@ void GrColorCubeEffect::GLProcessor::GenKey(const GrProcessor& proc,
 }
 
 bool SkColorCubeFilter::asFragmentProcessors(GrContext* context, GrProcessorDataManager*,
-                                             SkTDArray<GrFragmentProcessor*>* array) const {
+                                             SkTDArray<const GrFragmentProcessor*>* array) const {
     static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
     GrUniqueKey key;
     GrUniqueKey::Builder builder(&key, kDomain, 2);