All source types working for linear pipeline.

gm/SkLinearBitmapPipelineGM.cpp

Index: gm/SkLinearBitmapPipelineGM.cpp
diff --git a/gm/SkLinearBitmapPipelineGM.cpp b/gm/SkLinearBitmapPipelineGM.cpp
index 845e33979f5da0eba8c6589b980c9454d63871f5..0a66b9c4df357809c3e6b5f5051642e4f96f120f 100644
--- a/gm/SkLinearBitmapPipelineGM.cpp
+++ b/gm/SkLinearBitmapPipelineGM.cpp
@@ -121,7 +121,7 @@ static void draw_rect_fp(SkCanvas* canvas, const SkRect& r, SkColor c, const SkM
 
     SkLinearBitmapPipeline pipeline{
             inv, filterQuality,
-            SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode, 1.0f, pmsrc};
+            SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode, SK_ColorBLACK, pmsrc};
 
     for (int y = 0; y < ir.height(); y++) {
         pipeline.shadeSpan4f(0, y, dstBits, ir.width());