use Make instead of Create to return a shared shader

samplecode/SampleTiling.cpp

Index: samplecode/SampleTiling.cpp
diff --git a/samplecode/SampleTiling.cpp b/samplecode/SampleTiling.cpp
index ed244eb3d2ae6d1b41a1957f0f636e25de9e1203..125155e8d050e3a02713244f42c7a8b9b8445d08 100644
--- a/samplecode/SampleTiling.cpp
+++ b/samplecode/SampleTiling.cpp
@@ -35,15 +35,14 @@ static void makebm(SkBitmap* bm, SkColorType ct, int w, int h) {
     SkPaint     paint;
 
     paint.setDither(true);
-    paint.setShader(SkGradientShader::CreateLinear(pts, colors, pos,
-                SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode))->unref();
+    paint.setShader(SkGradientShader::MakeLinear(pts, colors, pos,
+                SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode));
     canvas.drawPaint(paint);
 }
 
 static void setup(SkPaint* paint, const SkBitmap& bm, bool filter,
                   SkShader::TileMode tmx, SkShader::TileMode tmy) {
-    SkShader* shader = SkShader::CreateBitmapShader(bm, tmx, tmy);
-    paint->setShader(shader)->unref();
+    paint->setShader(SkShader::MakeBitmapShader(bm, tmx, tmy));
     paint->setFilterQuality(filter ? kLow_SkFilterQuality : kNone_SkFilterQuality);
 }