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/tests/GrTextureMipMapInvalidationTest.cpp b/tests/GrTextureMipMapInvalidationTest.cpp
index b047550..539a8ce 100644
--- a/tests/GrTextureMipMapInvalidationTest.cpp
+++ b/tests/GrTextureMipMapInvalidationTest.cpp
@@ -41,7 +41,7 @@
     REPORTER_ASSERT(reporter, false == tex->texturePriv().hasMipMaps());
 
     // Painting with downscale and medium filter quality should result in mipmap creation
-    SkSurface* surface = SkSurface::NewRenderTargetDirect(texRT2->asRenderTarget());
+    auto surface = SkSurface::MakeRenderTargetDirect(texRT2->asRenderTarget());
     SkPaint paint;
     paint.setFilterQuality(kMedium_SkFilterQuality);
     surface->getCanvas()->scale(0.2f, 0.2f);
@@ -56,7 +56,6 @@
     REPORTER_ASSERT(reporter, true == tex->texturePriv().hasMipMaps());
     REPORTER_ASSERT(reporter, true == tex->texturePriv().mipMapsAreDirty());
 
-    surface->unref();
     texRT1->unref();
     texRT2->unref();
 }