added support for PLS path rendering

src/effects/SkArithmeticMode_gpu.h

Index: src/effects/SkArithmeticMode_gpu.h
diff --git a/src/effects/SkArithmeticMode_gpu.h b/src/effects/SkArithmeticMode_gpu.h
index d6b1f881dff4a839a02d80e81d11fff328307a1d..18530e9e947ce4592627e9dbcb3fb4684d0e91e5 100644
--- a/src/effects/SkArithmeticMode_gpu.h
+++ b/src/effects/SkArithmeticMode_gpu.h
@@ -92,9 +92,9 @@ private:
                                            bool hasMixedSamples,
                                            const DstTexture*) const override; 
 
-    bool willReadDstColor(const GrCaps& caps,
-                          const GrPipelineOptimizations& optimizations,
-                          bool hasMixedSamples) const override {
+    bool onWillReadDstColor(const GrCaps& caps,
+                            const GrPipelineOptimizations& optimizations,
+                            bool hasMixedSamples) const override {
         return true;
     }