Pass in ProcOptInfos into willNeedDstCopy on XPs

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 ddcfb0b2f4c646bea6f08e1b464c9b6b8bc23af2..822e7bde1e0a360e6e5b31d59af87042fdef84d7 100644
--- a/src/effects/SkArithmeticMode_gpu.h
+++ b/src/effects/SkArithmeticMode_gpu.h
@@ -100,7 +100,10 @@ private:
                                            const GrProcOptInfo& coveragePOI,
                                            const GrDeviceCoordTexture* dstCopy) const SK_OVERRIDE; 
 
-    bool willReadDstColor() const SK_OVERRIDE { return true; }
+    bool willReadDstColor(const GrProcOptInfo& colorPOI,
+                          const GrProcOptInfo& coveragePOI) const SK_OVERRIDE {
+        return true;
+    }
 
     bool onIsEqual(const GrXPFactory& xpfBase) const SK_OVERRIDE {
         const GrArithmeticXPFactory& xpf = xpfBase.cast<GrArithmeticXPFactory>();