diff --git a/src/core/SkColorFilter_Matrix.cpp b/src/core/SkColorFilter_Matrix.cpp
index 6ae3d1844d..a0a047c345 100644
--- a/src/core/SkColorFilter_Matrix.cpp
+++ b/src/core/SkColorFilter_Matrix.cpp
@@ -229,65 +229,7 @@ static sk_sp<SkColorFilter> MakeMatrix(const float array[20],
     if (!sk_floats_are_finite(array, 20)) {
         return nullptr;
     }
-#if 1
     return sk_make_sp<SkColorFilter_Matrix>(array, domain);
-#else
-    const bool alphaUnchanged = SkScalarNearlyEqual(array[15], 0)
-                             && SkScalarNearlyEqual(array[16], 0)
-                             && SkScalarNearlyEqual(array[17], 0)
-                             && SkScalarNearlyEqual(array[18], 1)
-                             && SkScalarNearlyEqual(array[19], 0);
-
-    struct { SkM44 m; SkV4 b; } uniforms;
-    SkString code {
-        "uniform half4x4 m;"
-        "uniform half4   b;"
-    };
-    if (domain == SkColorFilter_Matrix::Domain::kHSLA) {
-        code += kRGB_to_HSL_sksl;
-        code += kHSL_to_RGB_sksl;
-    }
-
-    code += "half4 main(half4 inColor) {";
-    if (true) {
-        code += "half4 c = inColor;";  // unpremul
-    }
-    if (alphaUnchanged) {
-        code += "half a = c.a;";
-    }
-    if (domain == SkColorFilter_Matrix::Domain::kHSLA) {
-        code += "c.rgb = rgb_to_hsl(c.rgb);";
-    }
-    if (true) {
-        uniforms.m = SkM44{array[ 0], array[ 1], array[ 2], array[ 3],
-                           array[ 5], array[ 6], array[ 7], array[ 8],
-                           array[10], array[11], array[12], array[13],
-                           array[15], array[16], array[17], array[18]};
-        uniforms.b = SkV4{array[4], array[9], array[14], array[19]};
-        code += "c = m*c + b;";
-    }
-    if (domain == SkColorFilter_Matrix::Domain::kHSLA) {
-        code += "c.rgb = hsl_to_rgb(c.rgb);";
-    }
-    if (alphaUnchanged) {
-        code += "return half4(saturate(c.rgb), a);";
-    } else {
-        code += "return saturate(c);";
-    }
-    code += "}";
-
-    sk_sp<SkRuntimeEffect> effect = SkMakeCachedRuntimeEffect(SkRuntimeEffect::MakeForColorFilter,
-                                                              std::move(code));
-    SkASSERT(effect);
-
-    SkAlphaType       unpremul = kUnpremul_SkAlphaType;
-    return SkColorFilters::WithWorkingFormat(
-            effect->makeColorFilter(SkData::MakeWithCopy(&uniforms,sizeof(uniforms))),
-            nullptr/*keep dst TF encoding*/,
-            nullptr/*stay in dst gamut*/,
-            &unpremul);
-
-#endif
 }
 
 sk_sp<SkColorFilter> SkColorFilters::Matrix(const float array[20]) {
@@ -308,18 +250,4 @@ sk_sp<SkColorFilter> SkColorFilters::HSLAMatrix(const SkColorMatrix& cm) {
 
 void SkColorFilter_Matrix::RegisterFlattenables() {
     SK_REGISTER_FLATTENABLE(SkColorFilter_Matrix);
-
-    // This subclass was removed 4/2019
-    SkFlattenable::Register("SkColorMatrixFilterRowMajor255",
-                            [](SkReadBuffer& buffer) -> sk_sp<SkFlattenable> {
-        float matrix[20];
-        if (buffer.readScalarArray(matrix, 20)) {
-            matrix[ 4] *= (1.0f/255);
-            matrix[ 9] *= (1.0f/255);
-            matrix[14] *= (1.0f/255);
-            matrix[19] *= (1.0f/255);
-            return SkColorFilters::Matrix(matrix);
-        }
-        return nullptr;
-    });
 }