tests: s/SkAutoTUnref/sk_sp/

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4394

Change-Id: I088b3c6e2adff07abed1e8a50091cc0ec4a4109c
Reviewed-on: https://skia-review.googlesource.com/4394
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
diff --git a/tests/ImageCacheTest.cpp b/tests/ImageCacheTest.cpp
index c2cf2d9..6d1e1ac 100644
--- a/tests/ImageCacheTest.cpp
+++ b/tests/ImageCacheTest.cpp
@@ -121,8 +121,7 @@
         test_cache(reporter, cache, true);
     }
     {
-        SkAutoTUnref<SkDiscardableMemoryPool> pool(
-                SkDiscardableMemoryPool::Create(defLimit, nullptr));
+        sk_sp<SkDiscardableMemoryPool> pool(SkDiscardableMemoryPool::Create(defLimit, nullptr));
         gPool = pool.get();
         SkResourceCache cache(pool_factory);
         test_cache(reporter, cache, true);