Flush denorm half floats to zero.

src/core/SkLinearBitmapPipeline_sample.h

Index: src/core/SkLinearBitmapPipeline_sample.h
diff --git a/src/core/SkLinearBitmapPipeline_sample.h b/src/core/SkLinearBitmapPipeline_sample.h
index 78f46ff797d330250245f4be9bd013e0d093609b..78e8d673ed93a5eeabd0d78fa4eb6aef9c10dc5b 100644
--- a/src/core/SkLinearBitmapPipeline_sample.h
+++ b/src/core/SkLinearBitmapPipeline_sample.h
@@ -185,7 +185,7 @@ public:
     PixelConverter(const SkPixmap& srcPixmap) { }
 
     Sk4f toSk4f(const Element pixel) const {
-        return SkHalfToFloat_finite(pixel);
+        return SkHalfToFloat_finite_ftz(pixel);
     }
 };