use Make instead of Create to return a shared shader

samplecode/SampleAARectModes.cpp

Index: samplecode/SampleAARectModes.cpp
diff --git a/samplecode/SampleAARectModes.cpp b/samplecode/SampleAARectModes.cpp
index ae28925a428cbb8e3f4c8db9b11d3466e2673e05..43392235c9fed3a0fee0e1dfb9aad45176ca299c 100644
--- a/samplecode/SampleAARectModes.cpp
+++ b/samplecode/SampleAARectModes.cpp
@@ -61,7 +61,7 @@ static SkScalar drawCell(SkCanvas* canvas, SkXfermode* mode,
     return H;
 }
 
-static SkShader* make_bg_shader() {
+static sk_sp<SkShader> make_bg_shader() {
     SkBitmap bm;
     bm.allocN32Pixels(2, 2);
     *bm.getAddr32(0, 0) = *bm.getAddr32(1, 1) = 0xFFFFFFFF;
@@ -71,17 +71,17 @@ static SkShader* make_bg_shader() {
     SkMatrix m;
     m.setScale(SkIntToScalar(6), SkIntToScalar(6));
 
-    return SkShader::CreateBitmapShader(bm,
-                                        SkShader::kRepeat_TileMode,
-                                        SkShader::kRepeat_TileMode,
-                                        &m);
+    return SkShader::MakeBitmapShader(bm,
+                                      SkShader::kRepeat_TileMode,
+                                      SkShader::kRepeat_TileMode,
+                                      &m);
 }
 
 class AARectsModesView : public SampleView {
     SkPaint fBGPaint;
 public:
     AARectsModesView () {
-        fBGPaint.setShader(make_bg_shader())->unref();
+        fBGPaint.setShader(make_bg_shader());
     }
 
 protected: