Vulkan config in dm

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1872283003

Review URL: https://codereview.chromium.org/1872283003
diff --git a/src/gpu/vk/GrVkGpu.cpp b/src/gpu/vk/GrVkGpu.cpp
index 428c2ff..280346f 100644
--- a/src/gpu/vk/GrVkGpu.cpp
+++ b/src/gpu/vk/GrVkGpu.cpp
@@ -63,10 +63,10 @@
 
 GrGpu* GrVkGpu::Create(GrBackendContext backendContext, const GrContextOptions& options,
                        GrContext* context) {
-    SkAutoTUnref<const GrVkBackendContext> vkBackendContext(
-                                       reinterpret_cast<const GrVkBackendContext*>(backendContext));
+    const GrVkBackendContext* vkBackendContext =
+        reinterpret_cast<const GrVkBackendContext*>(backendContext);
     if (!vkBackendContext) {
-        vkBackendContext.reset(GrVkBackendContext::Create());
+        vkBackendContext = GrVkBackendContext::Create();
         if (!vkBackendContext) {
             return nullptr;
         }