switch surface to sk_sp

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1817383002
CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Release-CMake-Trybot,Build-Mac-Clang-x86_64-Release-CMake-Trybot

Review URL: https://codereview.chromium.org/1817383002
diff --git a/gm/image_shader.cpp b/gm/image_shader.cpp
index 0615390..5fed7d1 100644
--- a/gm/image_shader.cpp
+++ b/gm/image_shader.cpp
@@ -27,7 +27,7 @@
 typedef sk_sp<SkImage> (*ImageMakerProc)(GrContext*, SkPicture*, const SkImageInfo&);
 
 static sk_sp<SkImage> make_raster(GrContext*, SkPicture* pic, const SkImageInfo& info) {
-    SkAutoTUnref<SkSurface> surface(SkSurface::NewRaster(info));
+    auto surface(SkSurface::MakeRaster(info));
     surface->getCanvas()->clear(0);
     surface->getCanvas()->drawPicture(pic);
     return surface->makeImageSnapshot();
@@ -37,8 +37,7 @@
     if (!ctx) {
         return nullptr;
     }
-    SkAutoTUnref<SkSurface> surface(SkSurface::NewRenderTarget(ctx, SkBudgeted::kNo,
-                                                               info, 0));
+    auto surface(SkSurface::MakeRenderTarget(ctx, SkBudgeted::kNo, info));
     surface->getCanvas()->clear(0);
     surface->getCanvas()->drawPicture(pic);
     return surface->makeImageSnapshot();