Fix casting bug in GrArithmeticXP

BUG=skia:

Review URL: https://codereview.chromium.org/858373006

diff --git a/src/effects/SkArithmeticMode_gpu.cpp b/src/effects/SkArithmeticMode_gpu.cpp
index 48b7bcd..38bb904 100644 (file)
--- a/src/effects/SkArithmeticMode_gpu.cpp
+++ b/src/effects/SkArithmeticMode_gpu.cpp
@@ -213,7 +213,7 @@ GrArithmeticXP::GrArithmeticXP(float k1, float k2, float k3, float k4, bool enfo
     , fK3(k3)
     , fK4(k4)
     , fEnforcePMColor(enforcePMColor) {
-    this->initClassID<GrPorterDuffXferProcessor>();
+    this->initClassID<GrArithmeticXP>();
     this->setWillReadDstColor();
 }