revise row blits to keep intermediate precision so that color is preserved when blended against its…

gm/blend.cpp

Index: gm/blend.cpp
diff --git a/gm/blend.cpp b/gm/blend.cpp
index b20422f113c85e134e559dc5024f82177fb1388f..8aed292f92ea3fc3e230be8303412e66f9766d2b 100644
--- a/gm/blend.cpp
+++ b/gm/blend.cpp
@@ -16,20 +16,20 @@ DEF_SIMPLE_GM(blend, canvas, 300, 100) {
 
         p.setColor(SK_ColorRED);
         canvas->drawRect(SkRect::MakeXYWH(0,0,1,1), p);
-        p.setColor(0xFC008000);
+        p.setColor(0xFC208000);
         canvas->drawRect(SkRect::MakeXYWH(0,0,1,1), p);
 
         p.setColor(SK_ColorRED);
         canvas->drawRect(SkRect::MakeXYWH(1,0,1,1), p);
         canvas->saveLayer(nullptr, nullptr);
-            p.setColor(0xFC008000);
+            p.setColor(0xFC208000);
             canvas->drawRect(SkRect::MakeXYWH(1,0,1,1), p);
         canvas->restore();
 
         p.setColor(SK_ColorRED);
         canvas->drawRect(SkRect::MakeXYWH(2,0,1,1), p);
         canvas->saveLayerAlpha(nullptr, 0xFC);
-            p.setColor(sk_tool_utils::color_to_565(0xFF008000));
+            p.setColor(sk_tool_utils::color_to_565(0xFF208000));
             canvas->drawRect(SkRect::MakeXYWH(2,0,1,1), p);
         canvas->restore();
     canvas->restore();