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/DiscardableMemoryPoolTest.cpp b/tests/DiscardableMemoryPoolTest.cpp
index d1ba38a..79b257d 100644
--- a/tests/DiscardableMemoryPoolTest.cpp
+++ b/tests/DiscardableMemoryPoolTest.cpp
@@ -9,7 +9,7 @@
 #include "Test.h"
 
 DEF_TEST(DiscardableMemoryPool, reporter) {
-    SkAutoTUnref<SkDiscardableMemoryPool> pool(
+    sk_sp<SkDiscardableMemoryPool> pool(
         SkDiscardableMemoryPool::Create(1, nullptr));
     pool->setRAMBudget(3);
     REPORTER_ASSERT(reporter, 0 == pool->getRAMUsed());