Add mixed samples support to XPs

src/effects/SkArithmeticMode_gpu.cpp

Index: src/effects/SkArithmeticMode_gpu.cpp
diff --git a/src/effects/SkArithmeticMode_gpu.cpp b/src/effects/SkArithmeticMode_gpu.cpp
index 0d81c7966ce91fd3b3cf8953b90576271573f5d5..074cada0a05a0eabb57d63057f83df648ae26fa0 100644
--- a/src/effects/SkArithmeticMode_gpu.cpp
+++ b/src/effects/SkArithmeticMode_gpu.cpp
@@ -160,13 +160,8 @@ GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrArithmeticFP);
 
 class ArithmeticXP : public GrXferProcessor {
 public:
-    static GrXferProcessor* Create(float k1, float k2, float k3, float k4, bool enforcePMColor,
-                                   const DstTexture* dstTexture, bool willReadDstColor) {
-        return SkNEW_ARGS(ArithmeticXP, (k1, k2, k3, k4, enforcePMColor, dstTexture,
-                                         willReadDstColor));
-    }
-
-    ~ArithmeticXP() override {};
+    ArithmeticXP(const DstTexture*, bool hasMixedSamples,
+                 float k1, float k2, float k3, float k4, bool enforcePMColor);
 
     const char* name() const override { return "Arithmetic"; }
 
@@ -179,9 +174,6 @@ public:
     bool enforcePMColor() const { return fEnforcePMColor; }
 
 private:
-    ArithmeticXP(float k1, float k2, float k3, float k4, bool enforcePMColor,
-                   const DstTexture*, bool willReadDstColor);
-
     GrXferProcessor::OptFlags onGetOptimizations(const GrProcOptInfo& colorPOI,
                                                  const GrProcOptInfo& coveragePOI,
                                                  bool doesStencilWrite,
@@ -253,9 +245,9 @@ private:
 
 ///////////////////////////////////////////////////////////////////////////////
 
-ArithmeticXP::ArithmeticXP(float k1, float k2, float k3, float k4, bool enforcePMColor,
-                           const DstTexture* dstTexture, bool willReadDstColor)
-    : INHERITED(dstTexture, willReadDstColor)
+ArithmeticXP::ArithmeticXP(const DstTexture* dstTexture, bool hasMixedSamples,
+                           float k1, float k2, float k3, float k4, bool enforcePMColor)
+    : INHERITED(dstTexture, true, hasMixedSamples)
     , fK1(k1)
     , fK2(k2)
     , fK3(k3)
@@ -292,9 +284,10 @@ GrXferProcessor*
 GrArithmeticXPFactory::onCreateXferProcessor(const GrCaps& caps,
                                              const GrProcOptInfo& colorPOI,
                                              const GrProcOptInfo& coveragePOI,
+                                             bool hasMixedSamples,
                                              const DstTexture* dstTexture) const {
-    return ArithmeticXP::Create(fK1, fK2, fK3, fK4, fEnforcePMColor, dstTexture,
-                                this->willReadDstColor(caps, colorPOI, coveragePOI));
+    return SkNEW_ARGS(ArithmeticXP, (dstTexture, hasMixedSamples, fK1, fK2, fK3, fK4,
+                                     fEnforcePMColor));
 }