Add more specialized fragment builders

src/gpu/effects/GrYUVEffect.cpp

Index: src/gpu/effects/GrYUVEffect.cpp
diff --git a/src/gpu/effects/GrYUVEffect.cpp b/src/gpu/effects/GrYUVEffect.cpp
index 9fd643bdb94500105edd5f0366f2533a84c74c9e..ef1bf1bfd796d4cb81c992965db4ff149971bbdf 100644
--- a/src/gpu/effects/GrYUVEffect.cpp
+++ b/src/gpu/effects/GrYUVEffect.cpp
@@ -99,7 +99,7 @@ public:
         static void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*) {}
 
         void emitCode(EmitArgs& args) override {
-            GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
+            GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
 
             const char* colorSpaceMatrix = nullptr;
             fMatrixUni = args.fUniformHandler->addUniform(kFragment_GrShaderFlag,
@@ -225,7 +225,7 @@ public:
         GLSLProcessor() : fLastColorSpace(-1), fLastOutputChannels(-1) {}
 
         void emitCode(EmitArgs& args) override {
-            GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
+            GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
             OutputChannels oc = args.fFp.cast<RGBToYUVEffect>().outputChannels();
 
             SkString outputColor("rgbColor");