use Make instead of Create to return a shared shader

samplecode/SampleDegenerateTwoPtRadials.cpp

Index: samplecode/SampleDegenerateTwoPtRadials.cpp
diff --git a/samplecode/SampleDegenerateTwoPtRadials.cpp b/samplecode/SampleDegenerateTwoPtRadials.cpp
index 32b45374e6c7642abffe6676ec94f21a1a4ef73f..f1712022491e4e23ee2e0ce43d62b5de0b0ac26b 100644
--- a/samplecode/SampleDegenerateTwoPtRadials.cpp
+++ b/samplecode/SampleDegenerateTwoPtRadials.cpp
@@ -27,12 +27,10 @@ static void draw_gradient2(SkCanvas* canvas, const SkRect& rect, SkScalar delta)
     SkPoint c1 = { l + 3 * w / 5, t + h / 2 };
     SkScalar r0 = w / 5;
     SkScalar r1 = 2 * w / 5;
-    SkShader* s = SkGradientShader::CreateTwoPointConical(c0, r0, c1, r1, colors,
-                                                         pos, SK_ARRAY_COUNT(pos),
-                                                         SkShader::kClamp_TileMode);
     SkPaint paint;
-    paint.setShader(s)->unref();
-
+    paint.setShader(SkGradientShader::MakeTwoPointConical(c0, r0, c1, r1, colors,
+                                                          pos, SK_ARRAY_COUNT(pos),
+                                                          SkShader::kClamp_TileMode));
     canvas->drawRect(rect, paint);
 }