guard rasterizer and drawlooper setters

samplecode/SampleTextOnPath.cpp

Index: samplecode/SampleTextOnPath.cpp
diff --git a/samplecode/SampleTextOnPath.cpp b/samplecode/SampleTextOnPath.cpp
index ea2ae81dc0e491098a4f2b320fd6239ee3c5e543..7c71084dbbff007184d2771cc65ed6664608a97e 100644
--- a/samplecode/SampleTextOnPath.cpp
+++ b/samplecode/SampleTextOnPath.cpp
@@ -35,10 +35,8 @@ static void textStrokePath(SkCanvas* canvas) {
 
     canvas->drawPath(path, paint);
 
-    paint.setLooper(SkBlurDrawLooper::Create(SK_ColorBLACK,
-                                             SkBlurMask::ConvertRadiusToSigma(0.002f),
-                                             0.0f,
-                                             0.0f))->unref();
+    paint.setLooper(SkBlurDrawLooper::Make(SK_ColorBLACK, SkBlurMask::ConvertRadiusToSigma(0.002f),
+                                           0.0f, 0.0f));
 
     const char* text = "DRAWING STROKED TEXT WITH A BLUR ON A PATH";
     size_t      len = strlen(text);