added support for PLS path rendering

src/gpu/effects/GrDisableColorXP.cpp

Index: src/gpu/effects/GrDisableColorXP.cpp
diff --git a/src/gpu/effects/GrDisableColorXP.cpp b/src/gpu/effects/GrDisableColorXP.cpp
index 70e40e4a14aeb0c49c4afec71bbc25ac8c69ec19..937bea8c35b5f1b7058a262a5cbc773f5b59e41d 100644
--- a/src/gpu/effects/GrDisableColorXP.cpp
+++ b/src/gpu/effects/GrDisableColorXP.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "effects/GrDisableColorXP.h"
+#include "GrPipeline.h"
 #include "GrProcessor.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 #include "glsl/GrGLSLProgramDataManager.h"
@@ -97,6 +98,7 @@ GrDisableColorXPFactory::onCreateXferProcessor(const GrCaps& caps,
                                                const GrPipelineOptimizations& optimizations,
                                                bool hasMixedSamples,
                                                const DstTexture* dst) const {
+    SkASSERT(!optimizations.fOverrides.fUsePLSDstRead);
     return DisableColorXP::Create();
 }