4 files changed, 22 insertions, 5 deletions
diff --git a/src/gpu/GrFragmentProcessor.cpp b/src/gpu/GrFragmentProcessor.cpp
index 0c7c06fd6a..187a17701d 100644
--- a/src/gpu/GrFragmentProcessor.cpp
+++ b/src/gpu/GrFragmentProcessor.cpp
@@ -103,7 +103,7 @@ bool GrFragmentProcessor::hasSameTransforms(const GrFragmentProcessor& that) con
     return true;
 }
 
-std::unique_ptr<GrFragmentProcessor> GrFragmentProcessor::MulOutputByInputAlpha(
+std::unique_ptr<GrFragmentProcessor> GrFragmentProcessor::MulChildByInputAlpha(
         std::unique_ptr<GrFragmentProcessor> fp) {
     if (!fp) {
         return nullptr;
@@ -111,6 +111,14 @@ std::unique_ptr<GrFragmentProcessor> GrFragmentProcessor::MulOutputByInputAlpha(
     return GrXfermodeFragmentProcessor::MakeFromDstProcessor(std::move(fp), SkBlendMode::kDstIn);
 }
 
+std::unique_ptr<GrFragmentProcessor> GrFragmentProcessor::MulInputByChildAlpha(
+        std::unique_ptr<GrFragmentProcessor> fp) {
+    if (!fp) {
+        return nullptr;
+    }
+    return GrXfermodeFragmentProcessor::MakeFromDstProcessor(std::move(fp), SkBlendMode::kSrcIn);
+}
+
 std::unique_ptr<GrFragmentProcessor> GrFragmentProcessor::PremulInput(
         std::unique_ptr<GrFragmentProcessor> fp) {
     if (!fp) {
diff --git a/src/gpu/GrFragmentProcessor.h b/src/gpu/GrFragmentProcessor.h
index 4ec92627ad..fa674d5d80 100644
--- a/src/gpu/GrFragmentProcessor.h
+++ b/src/gpu/GrFragmentProcessor.h
@@ -33,8 +33,17 @@ public:
     *  does so by returning a parent FP that multiplies the passed in FPs output by the parent's
     *  input alpha. The passed in FP will not receive an input color.
     */
-    static std::unique_ptr<GrFragmentProcessor> MulOutputByInputAlpha(
-            std::unique_ptr<GrFragmentProcessor>);
+    static std::unique_ptr<GrFragmentProcessor> MulChildByInputAlpha(
+            std::unique_ptr<GrFragmentProcessor> child);
+
+    /**
+     *  Like MulChildByInputAlpha(), but reverses the sense of src and dst. In this case, return
+     *  the input modulated by the child's alpha. The passed in FP will not receive an input color.
+     *
+     *  output = input * child.a
+     */
+    static std::unique_ptr<GrFragmentProcessor> MulInputByChildAlpha(
+            std::unique_ptr<GrFragmentProcessor> child);
 
     /**
      *  This assumes that the input color to the returned processor will be unpremul and that the
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index 080d993c68..73e5f11e4a 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -1094,7 +1094,7 @@ void SkGpuDevice::drawSpecial(SkSpecialImage* special1, int left, int top, const
     if (GrPixelConfigIsAlphaOnly(config)) {
         fp = GrFragmentProcessor::MakeInputPremulAndMulByOutput(std::move(fp));
     } else {
-        fp = GrFragmentProcessor::MulOutputByInputAlpha(std::move(fp));
+        fp = GrFragmentProcessor::MulChildByInputAlpha(std::move(fp));
     }
 
     GrPaint grPaint;
diff --git a/src/gpu/SkGr.cpp b/src/gpu/SkGr.cpp
index a702d06395..af0579a098 100644
--- a/src/gpu/SkGr.cpp
+++ b/src/gpu/SkGr.cpp
@@ -576,7 +576,7 @@ bool SkPaintToGrPaintWithTexture(GrContext* context,
             shaderFP = GrFragmentProcessor::MakeInputPremulAndMulByOutput(std::move(fp));
         }
     } else {
-        shaderFP = GrFragmentProcessor::MulOutputByInputAlpha(std::move(fp));
+        shaderFP = GrFragmentProcessor::MulChildByInputAlpha(std::move(fp));
     }
 
     return SkPaintToGrPaintReplaceShader(context, colorSpaceInfo, paint, std::move(shaderFP),