remove shadeSpan16 from shader

src/core/SkFilterShader.cpp

Index: src/core/SkFilterShader.cpp
diff --git a/src/core/SkFilterShader.cpp b/src/core/SkFilterShader.cpp
index b52c2be8c4f56ead898b2f018206efd9ec869ca9..2f07c23d95d99299b13541dafd9ab1877dde5050 100644
--- a/src/core/SkFilterShader.cpp
+++ b/src/core/SkFilterShader.cpp
@@ -46,9 +46,6 @@ uint32_t SkFilterShader::FilterShaderContext::getFlags() const {
     uint32_t shaderF = fShaderContext->getFlags();
     uint32_t filterF = filterShader.fFilter->getFlags();
 
-    // filters don't support 16bit, so clear the matching bit in the shader
-    shaderF &= ~SkShader::kHasSpan16_Flag;
-
     // if the filter might change alpha, clear the opaque flag in the shader
     if (!(filterF & SkColorFilter::kAlphaUnchanged_Flag)) {
         shaderF &= ~SkShader::kOpaqueAlpha_Flag;