Check PremulType during GrGradientEffect::onIsEqual

src/effects/gradients/SkGradientShader.cpp

Index: src/effects/gradients/SkGradientShader.cpp
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index c64085c86aed3ad8b9b9d17179dcd2e5c6b43779..52fbe81daf454925cefdf472c07b04a5ee81efb9 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -1157,12 +1157,14 @@ bool GrGradientEffect::onIsEqual(const GrFragmentProcessor& processor) const {
     if (this->fColorType == s.getColorType()){
 
         if (SkGradientShaderBase::kTwo_GpuColorType == fColorType) {
-            if (*this->getColors(0) != *s.getColors(0) ||
+            if (this->getPremulType() != s.getPremulType() ||
+                *this->getColors(0) != *s.getColors(0) ||
                 *this->getColors(1) != *s.getColors(1)) {
                 return false;
             }
         } else if (SkGradientShaderBase::kThree_GpuColorType == fColorType) {
-            if (*this->getColors(0) != *s.getColors(0) ||
+            if (this->getPremulType() != s.getPremulType() ||
+                *this->getColors(0) != *s.getColors(0) ||
                 *this->getColors(1) != *s.getColors(1) ||
                 *this->getColors(2) != *s.getColors(2)) {
                 return false;