partial switch over to sp usage of shaders

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1776973003

Review URL: https://codereview.chromium.org/1776973003
diff --git a/gm/bmpfilterqualityrepeat.cpp b/gm/bmpfilterqualityrepeat.cpp
index c147014..b32a99a 100644
--- a/gm/bmpfilterqualityrepeat.cpp
+++ b/gm/bmpfilterqualityrepeat.cpp
@@ -60,7 +60,7 @@
             lm.setTranslateY(330);
 
             static const SkShader::TileMode kTM = SkShader::kRepeat_TileMode;
-            bmpPaint.setShader(SkShader::CreateBitmapShader(fBmp, kTM, kTM, &lm))->unref();
+            bmpPaint.setShader(SkShader::MakeBitmapShader(fBmp, kTM, kTM, &lm));
             SkRect rect = SkRect::MakeLTRB(20, 60, 220, 210);
             canvas->drawRect(rect, bmpPaint);
             paint.setAntiAlias(true);