Replace RenderEngineResult with FenceResult

Bug: b/232535621
Test: refactor, existing tests pass

Change-Id: I86fe498246e45d199a47008a3fb90af3030e83d6
diff --git a/graphics/composer/2.2/utils/vts/RenderEngineVts.cpp b/graphics/composer/2.2/utils/vts/RenderEngineVts.cpp
index 4a33fb5..1700b2a 100644
--- a/graphics/composer/2.2/utils/vts/RenderEngineVts.cpp
+++ b/graphics/composer/2.2/utils/vts/RenderEngineVts.cpp
@@ -71,14 +71,12 @@
                    });
     auto texture = std::make_shared<renderengine::impl::ExternalTexture>(
             mGraphicBuffer, *mRenderEngine, renderengine::impl::ExternalTexture::Usage::WRITEABLE);
-    auto [status, readyFence] = mRenderEngine
-                                        ->drawLayers(mDisplaySettings, compositionLayers, texture,
-                                                     true, std::move(bufferFence))
-                                        .get();
-    int fd = readyFence.release();
-    if (fd != -1) {
-        ASSERT_EQ(0, sync_wait(fd, -1));
-        ASSERT_EQ(0, close(fd));
+    auto result = mRenderEngine
+                          ->drawLayers(mDisplaySettings, compositionLayers, texture, true,
+                                       std::move(bufferFence))
+                          .get();
+    if (result.ok()) {
+        result.value()->waitForever(LOG_TAG);
     }
 }
 
diff --git a/graphics/composer/aidl/vts/RenderEngineVts.cpp b/graphics/composer/aidl/vts/RenderEngineVts.cpp
index 71b011c..66779c8 100644
--- a/graphics/composer/aidl/vts/RenderEngineVts.cpp
+++ b/graphics/composer/aidl/vts/RenderEngineVts.cpp
@@ -66,14 +66,12 @@
     auto texture = std::make_shared<::android::renderengine::impl::ExternalTexture>(
             mGraphicBuffer, *mRenderEngine,
             ::android::renderengine::impl::ExternalTexture::Usage::WRITEABLE);
-    auto [status, readyFence] = mRenderEngine
-                                        ->drawLayers(mDisplaySettings, compositionLayers, texture,
-                                                     true, std::move(bufferFence))
-                                        .get();
-    int fd = readyFence.release();
-    if (fd != -1) {
-        ASSERT_EQ(0, sync_wait(fd, -1));
-        ASSERT_EQ(0, close(fd));
+    auto result = mRenderEngine
+                          ->drawLayers(mDisplaySettings, compositionLayers, texture, true,
+                                       std::move(bufferFence))
+                          .get();
+    if (result.ok()) {
+        result.value()->waitForever(LOG_TAG);
     }
 }