diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/FenceResult.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/FenceResult.h
deleted file mode 100644
index 0ce263b..0000000
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/FenceResult.h
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- * Copyright 2022 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#pragma once
-
-#include <android-base/expected.h>
-#include <utils/Errors.h>
-#include <utils/StrongPointer.h>
-
-// TODO(b/232535621): Pull this file to <ui/FenceResult.h> so that RenderEngine::drawLayers returns
-// FenceResult rather than RenderEngineResult.
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wconversion"
-#include <renderengine/RenderEngine.h>
-#pragma clang diagnostic pop
-
-namespace android {
-
-class Fence;
-
-using FenceResult = base::expected<sp<Fence>, status_t>;
-
-// TODO(b/232535621): Prevent base::unexpected(NO_ERROR) from being a valid FenceResult.
-inline status_t fenceStatus(const FenceResult& fenceResult) {
-    return fenceResult.ok() ? NO_ERROR : fenceResult.error();
-}
-
-inline FenceResult toFenceResult(renderengine::RenderEngineResult&& result) {
-    if (auto [status, fence] = std::move(result); fence.ok()) {
-        return sp<Fence>::make(std::move(fence));
-    } else {
-        return base::unexpected(status);
-    }
-}
-
-} // namespace android
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h
index f93fd99..9753a6c 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h
@@ -20,8 +20,6 @@
 #include <ostream>
 #include <unordered_set>
 
-#include <compositionengine/FenceResult.h>
-
 // TODO(b/129481165): remove the #pragma below and fix conversion issues
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wconversion"
@@ -33,6 +31,7 @@
 #pragma clang diagnostic pop // ignored "-Wconversion -Wextra"
 
 #include <ftl/future.h>
+#include <ui/FenceResult.h>
 #include <utils/RefBase.h>
 #include <utils/Timers.h>
 
diff --git a/services/surfaceflinger/CompositionEngine/src/Output.cpp b/services/surfaceflinger/CompositionEngine/src/Output.cpp
index 06ae9e9..ea78517 100644
--- a/services/surfaceflinger/CompositionEngine/src/Output.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/Output.cpp
@@ -1330,11 +1330,10 @@
     // over to RenderEngine, in which case this flag can be removed from the drawLayers interface.
     const bool useFramebufferCache = outputState.layerFilter.toInternalDisplay;
 
-    auto fenceResult =
-            toFenceResult(renderEngine
-                                  .drawLayers(clientCompositionDisplay, clientRenderEngineLayers,
-                                              tex, useFramebufferCache, std::move(fd))
-                                  .get());
+    auto fenceResult = renderEngine
+                               .drawLayers(clientCompositionDisplay, clientRenderEngineLayers, tex,
+                                           useFramebufferCache, std::move(fd))
+                               .get();
 
     if (mClientCompositionRequestCache && fenceStatus(fenceResult) != NO_ERROR) {
         // If rendering was not successful, remove the request from the cache.
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp b/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
index 3315767..0731d48 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
@@ -273,11 +273,10 @@
 
     constexpr bool kUseFramebufferCache = false;
 
-    auto fenceResult =
-            toFenceResult(renderEngine
-                                  .drawLayers(displaySettings, layerSettings, texture->get(),
-                                              kUseFramebufferCache, std::move(bufferFence))
-                                  .get());
+    auto fenceResult = renderEngine
+                               .drawLayers(displaySettings, layerSettings, texture->get(),
+                                           kUseFramebufferCache, std::move(bufferFence))
+                               .get();
 
     if (fenceStatus(fenceResult) == NO_ERROR) {
         mDrawFence = std::move(fenceResult).value_or(Fence::NO_FENCE);
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
index 163a11c..ace2864 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
@@ -39,7 +39,6 @@
 #include "CallOrderStateMachineHelper.h"
 #include "MockHWC2.h"
 #include "RegionMatcher.h"
-#include "TestUtils.h"
 
 namespace android::compositionengine {
 namespace {
@@ -3527,9 +3526,8 @@
             .WillRepeatedly([&](const renderengine::DisplaySettings&,
                                 const std::vector<renderengine::LayerSettings>&,
                                 const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                                base::unique_fd&&)
-                                    -> std::future<renderengine::RenderEngineResult> {
-                return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
+                return ftl::yield<FenceResult>(Fence::NO_FENCE);
             });
     verify().execute().expectAFenceWasReturned();
 }
@@ -3559,9 +3557,8 @@
             .WillRepeatedly([&](const renderengine::DisplaySettings&,
                                 const std::vector<renderengine::LayerSettings>&,
                                 const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                                base::unique_fd&&)
-                                    -> std::future<renderengine::RenderEngineResult> {
-                return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
+                return ftl::yield<FenceResult>(Fence::NO_FENCE);
             });
 
     verify().execute().expectAFenceWasReturned();
@@ -3594,9 +3591,8 @@
             .WillRepeatedly([&](const renderengine::DisplaySettings&,
                                 const std::vector<renderengine::LayerSettings>&,
                                 const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                                base::unique_fd&&)
-                                    -> std::future<renderengine::RenderEngineResult> {
-                return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
+                return ftl::yield<FenceResult>(Fence::NO_FENCE);
             });
 
     verify().execute().expectAFenceWasReturned();
@@ -3622,10 +3618,8 @@
     EXPECT_CALL(*mRenderSurface, dequeueBuffer(_)).WillRepeatedly(Return(mOutputBuffer));
     EXPECT_CALL(mRenderEngine, drawLayers(_, ElementsAre(r1, r2), _, false, _))
             .Times(2)
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))))
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
 
     verify().execute().expectAFenceWasReturned();
     EXPECT_FALSE(mOutput.mState.reusedClientComposition);
@@ -3653,8 +3647,7 @@
 
     EXPECT_CALL(*mRenderSurface, dequeueBuffer(_)).WillRepeatedly(Return(mOutputBuffer));
     EXPECT_CALL(mRenderEngine, drawLayers(_, ElementsAre(r1, r2), _, false, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     EXPECT_CALL(mOutput, setExpensiveRenderingExpected(false));
 
     verify().execute().expectAFenceWasReturned();
@@ -3693,9 +3686,8 @@
             .WillRepeatedly([&](const renderengine::DisplaySettings&,
                                 const std::vector<renderengine::LayerSettings>&,
                                 const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                                base::unique_fd&&)
-                                    -> std::future<renderengine::RenderEngineResult> {
-                return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
+                return ftl::yield<FenceResult>(Fence::NO_FENCE);
             });
 
     verify().execute().expectAFenceWasReturned();
@@ -3726,11 +3718,9 @@
 
     EXPECT_CALL(*mRenderSurface, dequeueBuffer(_)).WillRepeatedly(Return(mOutputBuffer));
     EXPECT_CALL(mRenderEngine, drawLayers(_, ElementsAre(r1, r2), _, false, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     EXPECT_CALL(mRenderEngine, drawLayers(_, ElementsAre(r1, r3), _, false, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
 
     verify().execute().expectAFenceWasReturned();
     EXPECT_FALSE(mOutput.mState.reusedClientComposition);
@@ -3807,8 +3797,7 @@
           : public CallOrderStateMachineHelper<TestType, ExpectDisplaySettingsState> {
         auto thenExpectDisplaySettingsUsed(renderengine::DisplaySettings settings) {
             EXPECT_CALL(getInstance()->mRenderEngine, drawLayers(settings, _, _, false, _))
-                    .WillOnce(Return(ByMove(futureOf<renderengine::RenderEngineResult>(
-                            {NO_ERROR, base::unique_fd()}))));
+                    .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
             return nextState<ExecuteState>();
         }
     };
@@ -4061,14 +4050,12 @@
                 .WillRepeatedly(Return());
         EXPECT_CALL(*mRenderSurface, dequeueBuffer(_)).WillRepeatedly(Return(mOutputBuffer));
         EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, false, _))
-                .WillRepeatedly(
-                        [&](const renderengine::DisplaySettings&,
-                            const std::vector<renderengine::LayerSettings>&,
-                            const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                            base::unique_fd&&) -> std::future<renderengine::RenderEngineResult> {
-                            return futureOf<renderengine::RenderEngineResult>(
-                                    {NO_ERROR, base::unique_fd()});
-                        });
+                .WillRepeatedly([&](const renderengine::DisplaySettings&,
+                                    const std::vector<renderengine::LayerSettings>&,
+                                    const std::shared_ptr<renderengine::ExternalTexture>&,
+                                    const bool, base::unique_fd&&) -> ftl::Future<FenceResult> {
+                    return ftl::yield<FenceResult>(Fence::NO_FENCE);
+                });
     }
 
     Layer mLayer1;
@@ -4133,8 +4120,7 @@
     // Must happen after setting the protected content state.
     EXPECT_CALL(*mRenderSurface, dequeueBuffer(_)).WillRepeatedly(Return(mOutputBuffer));
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, false, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
 
     base::unique_fd fd;
     std::shared_ptr<renderengine::ExternalTexture> tex;
@@ -4226,8 +4212,7 @@
 
     EXPECT_CALL(mOutput, setExpensiveRenderingExpected(true));
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, false, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
 
     base::unique_fd fd;
     std::shared_ptr<renderengine::ExternalTexture> tex;
@@ -4250,8 +4235,7 @@
         EXPECT_CALL(mOutput, generateClientCompositionRequests(_, kDefaultOutputDataspace, _))
                 .WillOnce(Return(std::vector<LayerFE::LayerSettings>{}));
         EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, false, _))
-                .WillOnce(Return(ByMove(futureOf<renderengine::RenderEngineResult>(
-                        {NO_ERROR, base::unique_fd()}))));
+                .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
         EXPECT_CALL(mOutput, getOutputLayerCount()).WillRepeatedly(Return(1u));
         EXPECT_CALL(mOutput, getOutputLayerOrderedByZByIndex(0u))
                 .WillRepeatedly(Return(&mLayer.outputLayer));
diff --git a/services/surfaceflinger/CompositionEngine/tests/TestUtils.h b/services/surfaceflinger/CompositionEngine/tests/TestUtils.h
deleted file mode 100644
index c80fde6..0000000
--- a/services/surfaceflinger/CompositionEngine/tests/TestUtils.h
+++ /dev/null
@@ -1,31 +0,0 @@
-/*
- * Copyright (C) 2021 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-#pragma once
-
-#include <future>
-
-namespace android::compositionengine {
-namespace {
-
-template <class T>
-std::future<T> futureOf(T obj) {
-    std::promise<T> resultPromise;
-    std::future<T> resultFuture = resultPromise.get_future();
-    resultPromise.set_value(std::move(obj));
-    return resultFuture;
-}
-} // namespace
-} // namespace android::compositionengine
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp
index 2b938d0..d5d688e 100644
--- a/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp
@@ -28,8 +28,6 @@
 #include <utils/Errors.h>
 #include <memory>
 
-#include "tests/TestUtils.h"
-
 namespace android::compositionengine {
 using namespace std::chrono_literals;
 
@@ -353,11 +351,10 @@
     clientComp2.emplace();
     clientComp2->alpha = 0.75f;
 
-    const auto drawLayers =
-            [&](const renderengine::DisplaySettings& displaySettings,
-                const std::vector<renderengine::LayerSettings>& layers,
-                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                base::unique_fd&&) -> std::future<renderengine::RenderEngineResult> {
+    const auto drawLayers = [&](const renderengine::DisplaySettings& displaySettings,
+                                const std::vector<renderengine::LayerSettings>& layers,
+                                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
         EXPECT_EQ(mOutputState.framebufferSpace.getContent(), displaySettings.physicalDisplay);
         EXPECT_EQ(mOutputState.layerStackSpace.getContent(), displaySettings.clip);
         EXPECT_EQ(ui::Transform::toRotationFlags(mOutputState.framebufferSpace.getOrientation()),
@@ -365,7 +362,7 @@
         EXPECT_EQ(0.5f, layers[0].alpha);
         EXPECT_EQ(0.75f, layers[1].alpha);
         EXPECT_EQ(ui::Dataspace::SRGB, displaySettings.outputDataspace);
-        return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+        return ftl::yield<FenceResult>(Fence::NO_FENCE);
     };
 
     EXPECT_CALL(*layerFE1, prepareClientComposition(ClientCompositionTargetSettingsSecureEq(false)))
@@ -403,11 +400,10 @@
     clientComp2.emplace();
     clientComp2->alpha = 0.75f;
 
-    const auto drawLayers =
-            [&](const renderengine::DisplaySettings& displaySettings,
-                const std::vector<renderengine::LayerSettings>& layers,
-                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                base::unique_fd&&) -> std::future<renderengine::RenderEngineResult> {
+    const auto drawLayers = [&](const renderengine::DisplaySettings& displaySettings,
+                                const std::vector<renderengine::LayerSettings>& layers,
+                                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
         EXPECT_EQ(mOutputState.framebufferSpace.getContent(), displaySettings.physicalDisplay);
         EXPECT_EQ(mOutputState.layerStackSpace.getContent(), displaySettings.clip);
         EXPECT_EQ(ui::Transform::toRotationFlags(mOutputState.framebufferSpace.getOrientation()),
@@ -416,7 +412,7 @@
         EXPECT_EQ(0.75f, layers[1].alpha);
         EXPECT_EQ(ui::Dataspace::SRGB, displaySettings.outputDataspace);
 
-        return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+        return ftl::yield<FenceResult>(Fence::NO_FENCE);
     };
 
     EXPECT_CALL(*layerFE1, prepareClientComposition(ClientCompositionTargetSettingsSecureEq(true)))
@@ -454,13 +450,12 @@
 
     mOutputState.displayBrightnessNits = 400.f;
 
-    const auto drawLayers =
-            [&](const renderengine::DisplaySettings& displaySettings,
-                const std::vector<renderengine::LayerSettings>&,
-                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                base::unique_fd&&) -> std::future<renderengine::RenderEngineResult> {
+    const auto drawLayers = [&](const renderengine::DisplaySettings& displaySettings,
+                                const std::vector<renderengine::LayerSettings>&,
+                                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
         EXPECT_EQ(mOutputState.displayBrightnessNits, displaySettings.targetLuminanceNits);
-        return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+        return ftl::yield<FenceResult>(Fence::NO_FENCE);
     };
 
     EXPECT_CALL(*layerFE1,
@@ -505,13 +500,12 @@
 
     mOutputState.displayBrightnessNits = 400.f;
 
-    const auto drawLayers =
-            [&](const renderengine::DisplaySettings& displaySettings,
-                const std::vector<renderengine::LayerSettings>&,
-                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                base::unique_fd&&) -> std::future<renderengine::RenderEngineResult> {
+    const auto drawLayers = [&](const renderengine::DisplaySettings& displaySettings,
+                                const std::vector<renderengine::LayerSettings>&,
+                                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
         EXPECT_EQ(mOutputState.displayBrightnessNits, displaySettings.targetLuminanceNits);
-        return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+        return ftl::yield<FenceResult>(Fence::NO_FENCE);
     };
 
     EXPECT_CALL(*layerFE1,
@@ -555,11 +549,10 @@
 
     mOutputState.framebufferSpace = ProjectionSpace(ui::Size(10, 20), Rect(2, 3, 10, 5));
 
-    const auto drawLayers =
-            [&](const renderengine::DisplaySettings& displaySettings,
-                const std::vector<renderengine::LayerSettings>& layers,
-                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                base::unique_fd&&) -> std::future<renderengine::RenderEngineResult> {
+    const auto drawLayers = [&](const renderengine::DisplaySettings& displaySettings,
+                                const std::vector<renderengine::LayerSettings>& layers,
+                                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
         EXPECT_EQ(mOutputState.framebufferSpace.getContent(), displaySettings.physicalDisplay);
         EXPECT_EQ(mOutputState.layerStackSpace.getContent(), displaySettings.clip);
         EXPECT_EQ(ui::Transform::toRotationFlags(mOutputState.framebufferSpace.getOrientation()),
@@ -568,7 +561,7 @@
         EXPECT_EQ(0.75f, layers[1].alpha);
         EXPECT_EQ(ui::Dataspace::SRGB, displaySettings.outputDataspace);
 
-        return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+        return ftl::yield<FenceResult>(Fence::NO_FENCE);
     };
 
     EXPECT_CALL(*layerFE1, prepareClientComposition(_)).WillOnce(Return(clientComp1));
@@ -786,11 +779,10 @@
     EXPECT_CALL(*layerFE2, prepareClientComposition(_)).WillOnce(Return(clientComp2));
     EXPECT_CALL(*layerFE3, prepareClientComposition(_)).WillOnce(Return(clientComp3));
 
-    const auto drawLayers =
-            [&](const renderengine::DisplaySettings&,
-                const std::vector<renderengine::LayerSettings>& layers,
-                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                base::unique_fd&&) -> std::future<renderengine::RenderEngineResult> {
+    const auto drawLayers = [&](const renderengine::DisplaySettings&,
+                                const std::vector<renderengine::LayerSettings>& layers,
+                                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
         // If the highlight layer is enabled, it will increase the size by 1.
         // We're interested in the third layer either way.
         EXPECT_GE(layers.size(), 4u);
@@ -810,7 +802,7 @@
             EXPECT_EQ(1.0f, holePunchBackgroundSettings.alpha);
         }
 
-        return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+        return ftl::yield<FenceResult>(Fence::NO_FENCE);
     };
 
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _)).WillOnce(Invoke(drawLayers));
@@ -847,11 +839,10 @@
     EXPECT_CALL(*layerFE2, prepareClientComposition(_)).WillOnce(Return(clientComp2));
     EXPECT_CALL(*layerFE3, prepareClientComposition(_)).WillOnce(Return(clientComp3));
 
-    const auto drawLayers =
-            [&](const renderengine::DisplaySettings&,
-                const std::vector<renderengine::LayerSettings>& layers,
-                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                base::unique_fd&&) -> std::future<renderengine::RenderEngineResult> {
+    const auto drawLayers = [&](const renderengine::DisplaySettings&,
+                                const std::vector<renderengine::LayerSettings>& layers,
+                                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
         // If the highlight layer is enabled, it will increase the size by 1.
         // We're interested in the third layer either way.
         EXPECT_GE(layers.size(), 4u);
@@ -872,7 +863,7 @@
             EXPECT_EQ(1.0f, holePunchBackgroundSettings.alpha);
         }
 
-        return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+        return ftl::yield<FenceResult>(Fence::NO_FENCE);
     };
 
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _)).WillOnce(Invoke(drawLayers));
@@ -999,11 +990,10 @@
                                 BackgroundBlurOnly)))
             .WillOnce(Return(clientComp3));
 
-    const auto drawLayers =
-            [&](const renderengine::DisplaySettings&,
-                const std::vector<renderengine::LayerSettings>& layers,
-                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
-                base::unique_fd&&) -> std::future<renderengine::RenderEngineResult> {
+    const auto drawLayers = [&](const renderengine::DisplaySettings&,
+                                const std::vector<renderengine::LayerSettings>& layers,
+                                const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
+                                base::unique_fd&&) -> ftl::Future<FenceResult> {
         // If the highlight layer is enabled, it will increase the size by 1.
         // We're interested in the third layer either way.
         EXPECT_GE(layers.size(), 3u);
@@ -1012,7 +1002,7 @@
         EXPECT_EQ(half3(0.0f, 0.0f, 0.0f), blurSettings.source.solidColor);
         EXPECT_EQ(0.0f, blurSettings.alpha);
 
-        return futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()});
+        return ftl::yield<FenceResult>(Fence::NO_FENCE);
     };
 
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _)).WillOnce(Invoke(drawLayers));
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
index 430a663..86cfee6 100644
--- a/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
@@ -27,8 +27,6 @@
 #include <renderengine/mock/RenderEngine.h>
 #include <chrono>
 
-#include "tests/TestUtils.h"
-
 namespace android::compositionengine {
 using namespace std::chrono_literals;
 using impl::planner::CachedSet;
@@ -171,8 +169,7 @@
 void FlattenerTest::expectAllLayersFlattened(const std::vector<const LayerState*>& layers) {
     // layers would be flattened but the buffer would not be overridden
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
 
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
@@ -423,8 +420,7 @@
     layerState1->resetFramesSinceBufferUpdate();
 
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
@@ -447,8 +443,7 @@
     mTime += 200ms;
 
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
@@ -500,8 +495,7 @@
     layerState3->resetFramesSinceBufferUpdate();
 
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
@@ -515,8 +509,7 @@
 
     // Layers 1 and 2 will be flattened a new drawFrame would be called for Layer4 and Layer5
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
@@ -545,8 +538,7 @@
     layerState3->incrementFramesSinceBufferUpdate();
     mTime += 200ms;
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
@@ -601,8 +593,7 @@
 
     // This will render a CachedSet.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     mFlattener->renderCachedSets(mOutputState, std::nullopt, true);
 
     // We've rendered a CachedSet, but we haven't merged it in.
@@ -666,8 +657,7 @@
 
     // This will render a CachedSet.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     mFlattener->renderCachedSets(mOutputState, std::nullopt, true);
 
     // We've rendered a CachedSet, but we haven't merged it in.
@@ -739,8 +729,7 @@
     // This will render a CachedSet of layer 0. Though it is just one layer, it satisfies the
     // exception that there would be a hole punch above it.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     mFlattener->renderCachedSets(mOutputState, std::nullopt, true);
 
     // We've rendered a CachedSet, but we haven't merged it in.
@@ -810,8 +799,7 @@
     // This will render a CachedSet of layer 0. Though it is just one layer, it satisfies the
     // exception that there would be a hole punch above it.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     mFlattener->renderCachedSets(mOutputState, std::nullopt, true);
 
     // We've rendered a CachedSet, but we haven't merged it in.
@@ -862,8 +850,7 @@
 
     // layers would be flattened but the buffer would not be overridden
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
 
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
@@ -908,8 +895,7 @@
 
     // layers would be flattened but the buffer would not be overridden
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillRepeatedly(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillRepeatedly(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
 
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
@@ -962,8 +948,7 @@
 
     // layers would be flattened but the buffer would not be overridden
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
 
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
@@ -1011,8 +996,7 @@
 
     // layers would be flattened but the buffer would not be overridden
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
 
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
@@ -1054,8 +1038,7 @@
     mTime += 200ms;
     // layers would be flattened but the buffer would not be overridden
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
 
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
@@ -1122,8 +1105,7 @@
     }
 
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     mFlattener->renderCachedSets(mOutputState,
                                  std::chrono::steady_clock::now() -
                                          (kCachedSetRenderDuration + 10ms),
@@ -1159,8 +1141,7 @@
 
     // This will render a CachedSet.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     mFlattener->renderCachedSets(mOutputState, std::nullopt, true);
 
     // We've rendered a CachedSet, but we haven't merged it in.
@@ -1210,8 +1191,7 @@
 
     // This will render a CachedSet.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     mFlattener->renderCachedSets(mOutputState, std::nullopt, true);
 
     // We've rendered a CachedSet, but we haven't merged it in.
@@ -1261,8 +1241,7 @@
 
     // This will render a CachedSet.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     mFlattener->renderCachedSets(mOutputState, std::nullopt, true);
 
     // We've rendered a CachedSet, but we haven't merged it in.
@@ -1315,8 +1294,7 @@
 
     // This will render a CachedSet.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     mFlattener->renderCachedSets(mOutputState, std::nullopt, true);
 
     // We've rendered a CachedSet, but we haven't merged it in.
@@ -1368,8 +1346,7 @@
 
     // This will render a CachedSet.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _))
-            .WillOnce(Return(ByMove(
-                    futureOf<renderengine::RenderEngineResult>({NO_ERROR, base::unique_fd()}))));
+            .WillOnce(Return(ByMove(ftl::yield<FenceResult>(Fence::NO_FENCE))));
     mFlattener->renderCachedSets(mOutputState, std::nullopt, true);
 
     // We've rendered a CachedSet, but we haven't merged it in.