move setshader to sk_sp, re-using SK_SUPPORT_LEGACY_CREATESHADER_PTR

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1829303002

Review URL: https://codereview.chromium.org/1829303002
diff --git a/tools/VisualBench/VisualBenchmarkStream.cpp b/tools/VisualBench/VisualBenchmarkStream.cpp
index b15ac7e..56780f8 100644
--- a/tools/VisualBench/VisualBenchmarkStream.cpp
+++ b/tools/VisualBench/VisualBenchmarkStream.cpp
@@ -56,8 +56,7 @@
         paint.setStrokeWidth(2);
 
         SkPaint perlinPaint;
-        perlinPaint.setShader(SkPerlinNoiseShader::CreateTurbulence(0.1f, 0.1f, 1, 0,
-                                                                    nullptr))->unref();
+        perlinPaint.setShader(SkPerlinNoiseShader::MakeTurbulence(0.1f, 0.1f, 1, 0, nullptr));
         for (int i = 0; i < loops; i++) {
             canvas->drawPath(fPath, paint);
             canvas->drawRect(fPerlinRect, perlinPaint);
diff --git a/tools/debugger/SkDrawCommand.cpp b/tools/debugger/SkDrawCommand.cpp
index 5dc6079..af1270c 100644
--- a/tools/debugger/SkDrawCommand.cpp
+++ b/tools/debugger/SkDrawCommand.cpp
@@ -1125,8 +1125,7 @@
         Json::Value jsonShader = jsonPaint[SKDEBUGCANVAS_ATTRIBUTE_SHADER];
         SkShader* shader = (SkShader*) load_flattenable(jsonShader, urlDataManager);
         if (shader != nullptr) {
-            target->setShader(shader);
-            shader->unref();
+            target->setShader(sk_ref_sp(shader));
         }
     }
 }