From ce13860281f833de8a3296b7a3dad9caced102e9 Mon Sep 17 00:00:00 2001
From: Andrew Clark <git@andrewclark.io>
Date: Thu, 28 Apr 2022 15:05:41 -0400
Subject: [PATCH] Remove enablePersistentOffscreenHostContainer flag (#24460)

This was a Fabric-related experiment that we ended up not shipping.
---
 .../src/ReactFabricHostConfig.js              |  32 ----
 .../src/createReactNoop.js                    | 179 +-----------------
 .../react-reconciler/src/ReactFiber.new.js    |  25 +--
 .../react-reconciler/src/ReactFiber.old.js    |  25 +--
 .../src/ReactFiberBeginWork.new.js            | 109 +----------
 .../src/ReactFiberBeginWork.old.js            | 109 +----------
 .../src/ReactFiberCompleteWork.new.js         |  72 +------
 .../src/ReactFiberCompleteWork.old.js         |  72 +------
 .../ReactFiberHostConfigWithNoPersistence.js  |   2 -
 .../src/ReactFiberThrow.new.js                |  25 ---
 .../src/ReactFiberThrow.old.js                |  25 ---
 .../src/forks/ReactFiberHostConfig.custom.js  |   4 -
 packages/shared/ReactFeatureFlags.js          |   1 -
 .../ReactFeatureFlags.native-fb-dynamic.js    |  18 +-
 .../forks/ReactFeatureFlags.native-fb.js      |   5 +-
 .../forks/ReactFeatureFlags.native-oss.js     |   1 -
 .../forks/ReactFeatureFlags.test-renderer.js  |   1 -
 .../ReactFeatureFlags.test-renderer.native.js |   1 -
 .../ReactFeatureFlags.test-renderer.www.js    |   1 -
 .../shared/forks/ReactFeatureFlags.testing.js |   1 -
 .../forks/ReactFeatureFlags.testing.www.js    |   1 -
 .../forks/ReactFeatureFlags.www-dynamic.js    |   1 -
 .../shared/forks/ReactFeatureFlags.www.js     |   2 -
 scripts/flow/xplat.js                         |   1 -
 24 files changed, 25 insertions(+), 688 deletions(-)

diff --git a/packages/react-native-renderer/src/ReactFabricHostConfig.js b/packages/react-native-renderer/src/ReactFabricHostConfig.js
index 81295f6e50f6..515c4e0f9665 100644
--- a/packages/react-native-renderer/src/ReactFabricHostConfig.js
+++ b/packages/react-native-renderer/src/ReactFabricHostConfig.js
@@ -7,7 +7,6 @@
  * @flow
  */
 
-import type {ReactNodeList, OffscreenMode} from 'shared/ReactTypes';
 import type {ElementRef} from 'react';
 import type {
   HostComponent,
@@ -545,37 +544,6 @@ export function cloneInstance(
   };
 }
 
-// TODO: These two methods should be replaced with `createOffscreenInstance` and
-// `cloneOffscreenInstance`. I did it this way for now because the offscreen
-// instance is stored on an extra HostComponent fiber instead of the
-// OffscreenComponent fiber, and I didn't want to add an extra check to the
-// generic HostComponent path. Instead we should use the OffscreenComponent
-// fiber, but currently Fabric expects a 1:1 correspondence between Fabric
-// instances and host fibers, so I'm leaving this optimization for later once
-// we can confirm this won't break any downstream expectations.
-export function getOffscreenContainerType(): string {
-  return 'RCTView';
-}
-
-export function getOffscreenContainerProps(
-  mode: OffscreenMode,
-  children: ReactNodeList,
-): Props {
-  if (mode === 'hidden') {
-    return {
-      children,
-      style: {display: 'none'},
-    };
-  } else {
-    return {
-      children,
-      style: {
-        flex: 1,
-      },
-    };
-  }
-}
-
 export function cloneHiddenInstance(
   instance: Instance,
   type: string,
diff --git a/packages/react-noop-renderer/src/createReactNoop.js b/packages/react-noop-renderer/src/createReactNoop.js
index 8e4050dcfa33..13a0f49105c2 100644
--- a/packages/react-noop-renderer/src/createReactNoop.js
+++ b/packages/react-noop-renderer/src/createReactNoop.js
@@ -19,7 +19,7 @@ import type {
   TransitionTracingCallbacks,
 } from 'react-reconciler/src/ReactInternalTypes';
 import type {UpdateQueue} from 'react-reconciler/src/ReactUpdateQueue';
-import type {ReactNodeList, OffscreenMode} from 'shared/ReactTypes';
+import type {ReactNodeList} from 'shared/ReactTypes';
 import type {RootTag} from 'react-reconciler/src/ReactRootTags';
 
 import * as Scheduler from 'scheduler/unstable_mock';
@@ -595,20 +595,6 @@ function createReactNoop(reconciler: Function, useMutation: boolean) {
           container.children = newChildren;
         },
 
-        getOffscreenContainerType(): string {
-          return 'offscreen';
-        },
-
-        getOffscreenContainerProps(
-          mode: OffscreenMode,
-          children: ReactNodeList,
-        ): Props {
-          return {
-            hidden: mode === 'hidden',
-            children,
-          };
-        },
-
         cloneHiddenInstance(
           instance: Instance,
           type: string,
@@ -721,9 +707,7 @@ function createReactNoop(reconciler: Function, useMutation: boolean) {
 
   function getChildren(root) {
     if (root) {
-      return useMutation
-        ? root.children
-        : removeOffscreenContainersFromChildren(root.children, false);
+      return root.children;
     } else {
       return null;
     }
@@ -731,169 +715,12 @@ function createReactNoop(reconciler: Function, useMutation: boolean) {
 
   function getPendingChildren(root) {
     if (root) {
-      return useMutation
-        ? root.children
-        : removeOffscreenContainersFromChildren(root.pendingChildren, false);
+      return root.children;
     } else {
       return null;
     }
   }
 
-  function removeOffscreenContainersFromChildren(children, hideNearestNode) {
-    // Mutation mode and persistent mode have different outputs for Offscreen
-    // and Suspense trees. Persistent mode adds an additional host node wrapper,
-    // whereas mutation mode does not.
-    //
-    // This function removes the offscreen host wrappers so that the output is
-    // consistent. If the offscreen node is hidden, it transfers the hiddenness
-    // to the child nodes, to mimic how it works in mutation mode. That way our
-    // tests don't have to fork tree assertions.
-    //
-    // So, it takes a tree that looks like this:
-    //
-    //    <offscreen hidden={true}>
-    //      <span>A</span>
-    //      <span>B</span>
-    //    </offscren>
-    //
-    // And turns it into this:
-    //
-    //   <span hidden={true}>A</span>
-    //   <span hidden={true}>B</span>
-    //
-    // We don't mutate the original tree, but instead return a copy.
-    //
-    // This function is only used by our test assertions, via the `getChildren`
-    // and `getChildrenAsJSX` methods.
-    let didClone = false;
-    const newChildren = [];
-    for (let i = 0; i < children.length; i++) {
-      const child = children[i];
-      const innerChildren = child.children;
-      if (innerChildren !== undefined) {
-        // This is a host instance instance
-        const instance: Instance = (child: any);
-        if (instance.type === 'offscreen') {
-          // This is an offscreen wrapper instance. Remove it from the tree
-          // and recursively return its children, as if it were a fragment.
-          didClone = true;
-          if (instance.text !== null) {
-            // If this offscreen tree contains only text, we replace it with
-            // a text child. Related to `shouldReplaceTextContent` feature.
-            const offscreenTextInstance: TextInstance = {
-              text: instance.text,
-              id: instanceCounter++,
-              parent: instance.parent,
-              hidden: hideNearestNode || instance.hidden,
-              context: instance.context,
-            };
-            // Hide from unit tests
-            Object.defineProperty(offscreenTextInstance, 'id', {
-              value: offscreenTextInstance.id,
-              enumerable: false,
-            });
-            Object.defineProperty(offscreenTextInstance, 'parent', {
-              value: offscreenTextInstance.parent,
-              enumerable: false,
-            });
-            Object.defineProperty(offscreenTextInstance, 'context', {
-              value: offscreenTextInstance.context,
-              enumerable: false,
-            });
-            newChildren.push(offscreenTextInstance);
-          } else {
-            // Skip the offscreen node and replace it with its children
-            const offscreenChildren = removeOffscreenContainersFromChildren(
-              innerChildren,
-              hideNearestNode || instance.hidden,
-            );
-            newChildren.push.apply(newChildren, offscreenChildren);
-          }
-        } else {
-          // This is a regular (non-offscreen) instance. If the nearest
-          // offscreen boundary is hidden, hide this node.
-          const hidden = hideNearestNode ? true : instance.hidden;
-          const clonedChildren = removeOffscreenContainersFromChildren(
-            instance.children,
-            // We never need to hide the children of this node, since if we're
-            // inside a hidden tree, then the hidden style will be applied to
-            // this node.
-            false,
-          );
-          if (
-            clonedChildren === instance.children &&
-            hidden === instance.hidden
-          ) {
-            // No changes. Reuse the original instance without cloning.
-            newChildren.push(instance);
-          } else {
-            didClone = true;
-            const clone: Instance = {
-              id: instance.id,
-              type: instance.type,
-              parent: instance.parent,
-              children: clonedChildren,
-              text: instance.text,
-              prop: instance.prop,
-              hidden: hideNearestNode ? true : instance.hidden,
-              context: instance.context,
-            };
-            Object.defineProperty(clone, 'id', {
-              value: clone.id,
-              enumerable: false,
-            });
-            Object.defineProperty(clone, 'parent', {
-              value: clone.parent,
-              enumerable: false,
-            });
-            Object.defineProperty(clone, 'text', {
-              value: clone.text,
-              enumerable: false,
-            });
-            Object.defineProperty(clone, 'context', {
-              value: clone.context,
-              enumerable: false,
-            });
-            newChildren.push(clone);
-          }
-        }
-      } else {
-        // This is a text instance
-        const textInstance: TextInstance = (child: any);
-        if (hideNearestNode) {
-          didClone = true;
-          const clone = {
-            text: textInstance.text,
-            id: textInstance.id,
-            parent: textInstance.parent,
-            hidden: textInstance.hidden || hideNearestNode,
-            context: textInstance.context,
-          };
-          Object.defineProperty(clone, 'id', {
-            value: clone.id,
-            enumerable: false,
-          });
-          Object.defineProperty(clone, 'parent', {
-            value: clone.parent,
-            enumerable: false,
-          });
-          Object.defineProperty(clone, 'context', {
-            value: clone.context,
-            enumerable: false,
-          });
-
-          newChildren.push(clone);
-        } else {
-          newChildren.push(textInstance);
-        }
-      }
-    }
-    // There are some tests that assume reference equality, so preserve it
-    // when possible. Alternatively, we could update the tests to compare the
-    // ids instead.
-    return didClone ? newChildren : children;
-  }
-
   function getChildrenAsJSX(root) {
     const children = childToJSX(getChildren(root), null);
     if (children === null) {
diff --git a/packages/react-reconciler/src/ReactFiber.new.js b/packages/react-reconciler/src/ReactFiber.new.js
index b28f1fee9b0e..33fc93ef9361 100644
--- a/packages/react-reconciler/src/ReactFiber.new.js
+++ b/packages/react-reconciler/src/ReactFiber.new.js
@@ -14,7 +14,7 @@ import type {RootTag} from './ReactRootTags';
 import type {WorkTag} from './ReactWorkTags';
 import type {TypeOfMode} from './ReactTypeOfMode';
 import type {Lanes} from './ReactFiberLane.new';
-import type {SuspenseInstance, Props} from './ReactFiberHostConfig';
+import type {SuspenseInstance} from './ReactFiberHostConfig';
 import type {
   OffscreenProps,
   OffscreenInstance,
@@ -32,10 +32,6 @@ import {
   enableTransitionTracing,
   enableDebugTracing,
 } from 'shared/ReactFeatureFlags';
-import {
-  supportsPersistence,
-  getOffscreenContainerType,
-} from './ReactFiberHostConfig';
 import {NoFlags, Placement, StaticMask} from './ReactFiberFlags';
 import {ConcurrentRoot} from './ReactRootTags';
 import {
@@ -605,25 +601,6 @@ export function createFiberFromTypeAndProps(
   return fiber;
 }
 
-export function createOffscreenHostContainerFiber(
-  props: Props,
-  fiberMode: TypeOfMode,
-  lanes: Lanes,
-  key: null | string,
-): Fiber {
-  if (supportsPersistence) {
-    const type = getOffscreenContainerType();
-    const fiber = createFiber(HostComponent, props, key, fiberMode);
-    fiber.elementType = type;
-    fiber.type = type;
-    fiber.lanes = lanes;
-    return fiber;
-  } else {
-    // Only implemented in persistent mode
-    throw new Error('Not implemented.');
-  }
-}
-
 export function createFiberFromElement(
   element: ReactElement,
   mode: TypeOfMode,
diff --git a/packages/react-reconciler/src/ReactFiber.old.js b/packages/react-reconciler/src/ReactFiber.old.js
index 5c4301977a3e..a65f460c6b27 100644
--- a/packages/react-reconciler/src/ReactFiber.old.js
+++ b/packages/react-reconciler/src/ReactFiber.old.js
@@ -14,7 +14,7 @@ import type {RootTag} from './ReactRootTags';
 import type {WorkTag} from './ReactWorkTags';
 import type {TypeOfMode} from './ReactTypeOfMode';
 import type {Lanes} from './ReactFiberLane.old';
-import type {SuspenseInstance, Props} from './ReactFiberHostConfig';
+import type {SuspenseInstance} from './ReactFiberHostConfig';
 import type {
   OffscreenProps,
   OffscreenInstance,
@@ -32,10 +32,6 @@ import {
   enableTransitionTracing,
   enableDebugTracing,
 } from 'shared/ReactFeatureFlags';
-import {
-  supportsPersistence,
-  getOffscreenContainerType,
-} from './ReactFiberHostConfig';
 import {NoFlags, Placement, StaticMask} from './ReactFiberFlags';
 import {ConcurrentRoot} from './ReactRootTags';
 import {
@@ -605,25 +601,6 @@ export function createFiberFromTypeAndProps(
   return fiber;
 }
 
-export function createOffscreenHostContainerFiber(
-  props: Props,
-  fiberMode: TypeOfMode,
-  lanes: Lanes,
-  key: null | string,
-): Fiber {
-  if (supportsPersistence) {
-    const type = getOffscreenContainerType();
-    const fiber = createFiber(HostComponent, props, key, fiberMode);
-    fiber.elementType = type;
-    fiber.type = type;
-    fiber.lanes = lanes;
-    return fiber;
-  } else {
-    // Only implemented in persistent mode
-    throw new Error('Not implemented.');
-  }
-}
-
 export function createFiberFromElement(
   element: ReactElement,
   mode: TypeOfMode,
diff --git a/packages/react-reconciler/src/ReactFiberBeginWork.new.js b/packages/react-reconciler/src/ReactFiberBeginWork.new.js
index 1538e32fca27..662ac5bbe59a 100644
--- a/packages/react-reconciler/src/ReactFiberBeginWork.new.js
+++ b/packages/react-reconciler/src/ReactFiberBeginWork.new.js
@@ -102,7 +102,6 @@ import {
   enableLazyContextPropagation,
   enableSuspenseLayoutEffectSemantics,
   enableSchedulingProfiler,
-  enablePersistentOffscreenHostContainer,
   enableTransitionTracing,
   enableLegacyHidden,
 } from 'shared/ReactFeatureFlags';
@@ -161,8 +160,6 @@ import {
   registerSuspenseInstanceRetry,
   supportsHydration,
   isPrimaryRenderer,
-  supportsPersistence,
-  getOffscreenContainerProps,
 } from './ReactFiberHostConfig';
 import type {SuspenseInstance} from './ReactFiberHostConfig';
 import {shouldError, shouldSuspend} from './ReactFiberReconciler';
@@ -226,7 +223,6 @@ import {
   createFiberFromFragment,
   createFiberFromOffscreen,
   createWorkInProgress,
-  createOffscreenHostContainerFiber,
   isSimpleFunctionComponent,
 } from './ReactFiber.new';
 import {
@@ -241,7 +237,6 @@ import {setWorkInProgressVersion} from './ReactMutableSource.new';
 import {pushCacheProvider, CacheContext} from './ReactFiberCacheComponent.new';
 import {createCapturedValue} from './ReactCapturedValue';
 import {createClassErrorUpdate} from './ReactFiberThrow.new';
-import {completeSuspendedOffscreenHostContainer} from './ReactFiberCompleteWork.new';
 import is from 'shared/objectIs';
 import {
   getForksAtLevel,
@@ -800,67 +795,8 @@ function updateOffscreenComponent(
     pushRenderLanes(workInProgress, subtreeRenderLanes);
   }
 
-  if (enablePersistentOffscreenHostContainer && supportsPersistence) {
-    // In persistent mode, the offscreen children are wrapped in a host node.
-    // TODO: Optimize this to use the OffscreenComponent fiber instead of
-    // an extra HostComponent fiber. Need to make sure this doesn't break Fabric
-    // or some other infra that expects a HostComponent.
-    const isHidden =
-      nextProps.mode === 'hidden' &&
-      (!enableLegacyHidden || workInProgress.tag !== LegacyHiddenComponent);
-    const offscreenContainer = reconcileOffscreenHostContainer(
-      current,
-      workInProgress,
-      isHidden,
-      nextChildren,
-      renderLanes,
-    );
-    return offscreenContainer;
-  } else {
-    reconcileChildren(current, workInProgress, nextChildren, renderLanes);
-    return workInProgress.child;
-  }
-}
-
-function reconcileOffscreenHostContainer(
-  currentOffscreen: Fiber | null,
-  offscreen: Fiber,
-  isHidden: boolean,
-  children: any,
-  renderLanes: Lanes,
-) {
-  const containerProps = getOffscreenContainerProps(
-    isHidden ? 'hidden' : 'visible',
-    children,
-  );
-  let hostContainer;
-  if (currentOffscreen === null) {
-    hostContainer = createOffscreenHostContainerFiber(
-      containerProps,
-      offscreen.mode,
-      renderLanes,
-      null,
-    );
-  } else {
-    const currentHostContainer = currentOffscreen.child;
-    if (currentHostContainer === null) {
-      hostContainer = createOffscreenHostContainerFiber(
-        containerProps,
-        offscreen.mode,
-        renderLanes,
-        null,
-      );
-      hostContainer.flags |= Placement;
-    } else {
-      hostContainer = createWorkInProgress(
-        currentHostContainer,
-        containerProps,
-      );
-    }
-  }
-  hostContainer.return = offscreen;
-  offscreen.child = hostContainer;
-  return hostContainer;
+  reconcileChildren(current, workInProgress, nextChildren, renderLanes);
+  return workInProgress.child;
 }
 
 // Note: These happen to have identical begin phases, for now. We shouldn't hold
@@ -2575,24 +2511,6 @@ function updateSuspenseFallbackChildren(
         currentPrimaryChildFragment.treeBaseDuration;
     }
 
-    if (enablePersistentOffscreenHostContainer && supportsPersistence) {
-      // In persistent mode, the offscreen children are wrapped in a host node.
-      // We need to complete it now, because we're going to skip over its normal
-      // complete phase and go straight to rendering the fallback.
-      const currentOffscreenContainer = currentPrimaryChildFragment.child;
-      const offscreenContainer: Fiber = (primaryChildFragment.child: any);
-      const containerProps = getOffscreenContainerProps(
-        'hidden',
-        primaryChildren,
-      );
-      offscreenContainer.pendingProps = containerProps;
-      offscreenContainer.memoizedProps = containerProps;
-      completeSuspendedOffscreenHostContainer(
-        currentOffscreenContainer,
-        offscreenContainer,
-      );
-    }
-
     // The fallback fiber was added as a deletion during the first pass.
     // However, since we're going to remain on the fallback, we no longer want
     // to delete it.
@@ -2602,29 +2520,6 @@ function updateSuspenseFallbackChildren(
       currentPrimaryChildFragment,
       primaryChildProps,
     );
-
-    if (enablePersistentOffscreenHostContainer && supportsPersistence) {
-      // In persistent mode, the offscreen children are wrapped in a host node.
-      // We need to complete it now, because we're going to skip over its normal
-      // complete phase and go straight to rendering the fallback.
-      const currentOffscreenContainer = currentPrimaryChildFragment.child;
-      if (currentOffscreenContainer !== null) {
-        const isHidden = true;
-        const offscreenContainer = reconcileOffscreenHostContainer(
-          currentPrimaryChildFragment,
-          primaryChildFragment,
-          isHidden,
-          primaryChildren,
-          renderLanes,
-        );
-        offscreenContainer.memoizedProps = offscreenContainer.pendingProps;
-        completeSuspendedOffscreenHostContainer(
-          currentOffscreenContainer,
-          offscreenContainer,
-        );
-      }
-    }
-
     // Since we're reusing a current tree, we need to reuse the flags, too.
     // (We don't do this in legacy mode, because in legacy mode we don't re-use
     // the current tree; see previous branch.)
diff --git a/packages/react-reconciler/src/ReactFiberBeginWork.old.js b/packages/react-reconciler/src/ReactFiberBeginWork.old.js
index c50ca6357a5d..81815280e07e 100644
--- a/packages/react-reconciler/src/ReactFiberBeginWork.old.js
+++ b/packages/react-reconciler/src/ReactFiberBeginWork.old.js
@@ -102,7 +102,6 @@ import {
   enableLazyContextPropagation,
   enableSuspenseLayoutEffectSemantics,
   enableSchedulingProfiler,
-  enablePersistentOffscreenHostContainer,
   enableTransitionTracing,
   enableLegacyHidden,
 } from 'shared/ReactFeatureFlags';
@@ -161,8 +160,6 @@ import {
   registerSuspenseInstanceRetry,
   supportsHydration,
   isPrimaryRenderer,
-  supportsPersistence,
-  getOffscreenContainerProps,
 } from './ReactFiberHostConfig';
 import type {SuspenseInstance} from './ReactFiberHostConfig';
 import {shouldError, shouldSuspend} from './ReactFiberReconciler';
@@ -226,7 +223,6 @@ import {
   createFiberFromFragment,
   createFiberFromOffscreen,
   createWorkInProgress,
-  createOffscreenHostContainerFiber,
   isSimpleFunctionComponent,
 } from './ReactFiber.old';
 import {
@@ -241,7 +237,6 @@ import {setWorkInProgressVersion} from './ReactMutableSource.old';
 import {pushCacheProvider, CacheContext} from './ReactFiberCacheComponent.old';
 import {createCapturedValue} from './ReactCapturedValue';
 import {createClassErrorUpdate} from './ReactFiberThrow.old';
-import {completeSuspendedOffscreenHostContainer} from './ReactFiberCompleteWork.old';
 import is from 'shared/objectIs';
 import {
   getForksAtLevel,
@@ -800,67 +795,8 @@ function updateOffscreenComponent(
     pushRenderLanes(workInProgress, subtreeRenderLanes);
   }
 
-  if (enablePersistentOffscreenHostContainer && supportsPersistence) {
-    // In persistent mode, the offscreen children are wrapped in a host node.
-    // TODO: Optimize this to use the OffscreenComponent fiber instead of
-    // an extra HostComponent fiber. Need to make sure this doesn't break Fabric
-    // or some other infra that expects a HostComponent.
-    const isHidden =
-      nextProps.mode === 'hidden' &&
-      (!enableLegacyHidden || workInProgress.tag !== LegacyHiddenComponent);
-    const offscreenContainer = reconcileOffscreenHostContainer(
-      current,
-      workInProgress,
-      isHidden,
-      nextChildren,
-      renderLanes,
-    );
-    return offscreenContainer;
-  } else {
-    reconcileChildren(current, workInProgress, nextChildren, renderLanes);
-    return workInProgress.child;
-  }
-}
-
-function reconcileOffscreenHostContainer(
-  currentOffscreen: Fiber | null,
-  offscreen: Fiber,
-  isHidden: boolean,
-  children: any,
-  renderLanes: Lanes,
-) {
-  const containerProps = getOffscreenContainerProps(
-    isHidden ? 'hidden' : 'visible',
-    children,
-  );
-  let hostContainer;
-  if (currentOffscreen === null) {
-    hostContainer = createOffscreenHostContainerFiber(
-      containerProps,
-      offscreen.mode,
-      renderLanes,
-      null,
-    );
-  } else {
-    const currentHostContainer = currentOffscreen.child;
-    if (currentHostContainer === null) {
-      hostContainer = createOffscreenHostContainerFiber(
-        containerProps,
-        offscreen.mode,
-        renderLanes,
-        null,
-      );
-      hostContainer.flags |= Placement;
-    } else {
-      hostContainer = createWorkInProgress(
-        currentHostContainer,
-        containerProps,
-      );
-    }
-  }
-  hostContainer.return = offscreen;
-  offscreen.child = hostContainer;
-  return hostContainer;
+  reconcileChildren(current, workInProgress, nextChildren, renderLanes);
+  return workInProgress.child;
 }
 
 // Note: These happen to have identical begin phases, for now. We shouldn't hold
@@ -2575,24 +2511,6 @@ function updateSuspenseFallbackChildren(
         currentPrimaryChildFragment.treeBaseDuration;
     }
 
-    if (enablePersistentOffscreenHostContainer && supportsPersistence) {
-      // In persistent mode, the offscreen children are wrapped in a host node.
-      // We need to complete it now, because we're going to skip over its normal
-      // complete phase and go straight to rendering the fallback.
-      const currentOffscreenContainer = currentPrimaryChildFragment.child;
-      const offscreenContainer: Fiber = (primaryChildFragment.child: any);
-      const containerProps = getOffscreenContainerProps(
-        'hidden',
-        primaryChildren,
-      );
-      offscreenContainer.pendingProps = containerProps;
-      offscreenContainer.memoizedProps = containerProps;
-      completeSuspendedOffscreenHostContainer(
-        currentOffscreenContainer,
-        offscreenContainer,
-      );
-    }
-
     // The fallback fiber was added as a deletion during the first pass.
     // However, since we're going to remain on the fallback, we no longer want
     // to delete it.
@@ -2602,29 +2520,6 @@ function updateSuspenseFallbackChildren(
       currentPrimaryChildFragment,
       primaryChildProps,
     );
-
-    if (enablePersistentOffscreenHostContainer && supportsPersistence) {
-      // In persistent mode, the offscreen children are wrapped in a host node.
-      // We need to complete it now, because we're going to skip over its normal
-      // complete phase and go straight to rendering the fallback.
-      const currentOffscreenContainer = currentPrimaryChildFragment.child;
-      if (currentOffscreenContainer !== null) {
-        const isHidden = true;
-        const offscreenContainer = reconcileOffscreenHostContainer(
-          currentPrimaryChildFragment,
-          primaryChildFragment,
-          isHidden,
-          primaryChildren,
-          renderLanes,
-        );
-        offscreenContainer.memoizedProps = offscreenContainer.pendingProps;
-        completeSuspendedOffscreenHostContainer(
-          currentOffscreenContainer,
-          offscreenContainer,
-        );
-      }
-    }
-
     // Since we're reusing a current tree, we need to reuse the flags, too.
     // (We don't do this in legacy mode, because in legacy mode we don't re-use
     // the current tree; see previous branch.)
diff --git a/packages/react-reconciler/src/ReactFiberCompleteWork.new.js b/packages/react-reconciler/src/ReactFiberCompleteWork.new.js
index 4cbae604140b..fe8f93e4d219 100644
--- a/packages/react-reconciler/src/ReactFiberCompleteWork.new.js
+++ b/packages/react-reconciler/src/ReactFiberCompleteWork.new.js
@@ -141,7 +141,6 @@ import {
   enableProfilerTimer,
   enableCache,
   enableSuspenseLayoutEffectSemantics,
-  enablePersistentOffscreenHostContainer,
   enableTransitionTracing,
 } from 'shared/ReactFeatureFlags';
 import {
@@ -347,11 +346,7 @@ if (supportsMutation) {
         if (child !== null) {
           child.return = node;
         }
-        if (enablePersistentOffscreenHostContainer) {
-          appendAllChildren(parent, node, false, false);
-        } else {
-          appendAllChildren(parent, node, true, true);
-        }
+        appendAllChildren(parent, node, true, true);
       } else if (node.child !== null) {
         node.child.return = node;
         node = node.child;
@@ -416,11 +411,7 @@ if (supportsMutation) {
         if (child !== null) {
           child.return = node;
         }
-        if (enablePersistentOffscreenHostContainer) {
-          appendAllChildrenToContainer(containerChildSet, node, false, false);
-        } else {
-          appendAllChildrenToContainer(containerChildSet, node, true, true);
-        }
+        appendAllChildrenToContainer(containerChildSet, node, true, true);
       } else if (node.child !== null) {
         node.child.return = node;
         node = node.child;
@@ -768,65 +759,6 @@ function bubbleProperties(completedWork: Fiber) {
   return didBailout;
 }
 
-export function completeSuspendedOffscreenHostContainer(
-  current: Fiber | null,
-  workInProgress: Fiber,
-) {
-  // This is a fork of the complete phase for HostComponent. We use it when
-  // a suspense tree is in its fallback state, because in that case the primary
-  // tree that includes the offscreen boundary is skipped over without a
-  // regular complete phase.
-  //
-  // We can optimize this path further by inlining the update logic for
-  // offscreen instances specifically, i.e. skipping the `prepareUpdate` call.
-  const rootContainerInstance = getRootHostContainer();
-  const type = workInProgress.type;
-  const newProps = workInProgress.memoizedProps;
-  if (current !== null) {
-    updateHostComponent(
-      current,
-      workInProgress,
-      type,
-      newProps,
-      rootContainerInstance,
-    );
-  } else {
-    const currentHostContext = getHostContext();
-    const instance = createInstance(
-      type,
-      newProps,
-      rootContainerInstance,
-      currentHostContext,
-      workInProgress,
-    );
-
-    appendAllChildren(instance, workInProgress, false, false);
-
-    workInProgress.stateNode = instance;
-
-    // Certain renderers require commit-time effects for initial mount.
-    // (eg DOM renderer supports auto-focus for certain elements).
-    // Make sure such renderers get scheduled for later work.
-    if (
-      finalizeInitialChildren(
-        instance,
-        type,
-        newProps,
-        rootContainerInstance,
-        currentHostContext,
-      )
-    ) {
-      markUpdate(workInProgress);
-    }
-
-    if (workInProgress.ref !== null) {
-      // If there is a ref on a host node we need to schedule a callback
-      markRef(workInProgress);
-    }
-  }
-  bubbleProperties(workInProgress);
-}
-
 function completeWork(
   current: Fiber | null,
   workInProgress: Fiber,
diff --git a/packages/react-reconciler/src/ReactFiberCompleteWork.old.js b/packages/react-reconciler/src/ReactFiberCompleteWork.old.js
index dd2703f396ee..abf1deb9ff38 100644
--- a/packages/react-reconciler/src/ReactFiberCompleteWork.old.js
+++ b/packages/react-reconciler/src/ReactFiberCompleteWork.old.js
@@ -141,7 +141,6 @@ import {
   enableProfilerTimer,
   enableCache,
   enableSuspenseLayoutEffectSemantics,
-  enablePersistentOffscreenHostContainer,
   enableTransitionTracing,
 } from 'shared/ReactFeatureFlags';
 import {
@@ -347,11 +346,7 @@ if (supportsMutation) {
         if (child !== null) {
           child.return = node;
         }
-        if (enablePersistentOffscreenHostContainer) {
-          appendAllChildren(parent, node, false, false);
-        } else {
-          appendAllChildren(parent, node, true, true);
-        }
+        appendAllChildren(parent, node, true, true);
       } else if (node.child !== null) {
         node.child.return = node;
         node = node.child;
@@ -416,11 +411,7 @@ if (supportsMutation) {
         if (child !== null) {
           child.return = node;
         }
-        if (enablePersistentOffscreenHostContainer) {
-          appendAllChildrenToContainer(containerChildSet, node, false, false);
-        } else {
-          appendAllChildrenToContainer(containerChildSet, node, true, true);
-        }
+        appendAllChildrenToContainer(containerChildSet, node, true, true);
       } else if (node.child !== null) {
         node.child.return = node;
         node = node.child;
@@ -768,65 +759,6 @@ function bubbleProperties(completedWork: Fiber) {
   return didBailout;
 }
 
-export function completeSuspendedOffscreenHostContainer(
-  current: Fiber | null,
-  workInProgress: Fiber,
-) {
-  // This is a fork of the complete phase for HostComponent. We use it when
-  // a suspense tree is in its fallback state, because in that case the primary
-  // tree that includes the offscreen boundary is skipped over without a
-  // regular complete phase.
-  //
-  // We can optimize this path further by inlining the update logic for
-  // offscreen instances specifically, i.e. skipping the `prepareUpdate` call.
-  const rootContainerInstance = getRootHostContainer();
-  const type = workInProgress.type;
-  const newProps = workInProgress.memoizedProps;
-  if (current !== null) {
-    updateHostComponent(
-      current,
-      workInProgress,
-      type,
-      newProps,
-      rootContainerInstance,
-    );
-  } else {
-    const currentHostContext = getHostContext();
-    const instance = createInstance(
-      type,
-      newProps,
-      rootContainerInstance,
-      currentHostContext,
-      workInProgress,
-    );
-
-    appendAllChildren(instance, workInProgress, false, false);
-
-    workInProgress.stateNode = instance;
-
-    // Certain renderers require commit-time effects for initial mount.
-    // (eg DOM renderer supports auto-focus for certain elements).
-    // Make sure such renderers get scheduled for later work.
-    if (
-      finalizeInitialChildren(
-        instance,
-        type,
-        newProps,
-        rootContainerInstance,
-        currentHostContext,
-      )
-    ) {
-      markUpdate(workInProgress);
-    }
-
-    if (workInProgress.ref !== null) {
-      // If there is a ref on a host node we need to schedule a callback
-      markRef(workInProgress);
-    }
-  }
-  bubbleProperties(workInProgress);
-}
-
 function completeWork(
   current: Fiber | null,
   workInProgress: Fiber,
diff --git a/packages/react-reconciler/src/ReactFiberHostConfigWithNoPersistence.js b/packages/react-reconciler/src/ReactFiberHostConfigWithNoPersistence.js
index 9f194fbc8a8d..c34449f6a246 100644
--- a/packages/react-reconciler/src/ReactFiberHostConfigWithNoPersistence.js
+++ b/packages/react-reconciler/src/ReactFiberHostConfigWithNoPersistence.js
@@ -25,7 +25,5 @@ export const createContainerChildSet = shim;
 export const appendChildToContainerChildSet = shim;
 export const finalizeContainerChildren = shim;
 export const replaceContainerChildren = shim;
-export const getOffscreenContainerType = shim;
-export const getOffscreenContainerProps = shim;
 export const cloneHiddenInstance = shim;
 export const cloneHiddenTextInstance = shim;
diff --git a/packages/react-reconciler/src/ReactFiberThrow.new.js b/packages/react-reconciler/src/ReactFiberThrow.new.js
index 7db27ba935d0..9a3d1b619235 100644
--- a/packages/react-reconciler/src/ReactFiberThrow.new.js
+++ b/packages/react-reconciler/src/ReactFiberThrow.new.js
@@ -34,17 +34,12 @@ import {
   ForceUpdateForLegacySuspense,
   ForceClientRender,
 } from './ReactFiberFlags';
-import {
-  supportsPersistence,
-  getOffscreenContainerProps,
-} from './ReactFiberHostConfig';
 import {shouldCaptureSuspense} from './ReactFiberSuspenseComponent.new';
 import {NoMode, ConcurrentMode, DebugTracingMode} from './ReactTypeOfMode';
 import {
   enableDebugTracing,
   enableLazyContextPropagation,
   enableUpdaterTracking,
-  enablePersistentOffscreenHostContainer,
 } from 'shared/ReactFeatureFlags';
 import {createCapturedValue} from './ReactCapturedValue';
 import {
@@ -336,26 +331,6 @@ function markSuspenseBoundaryShouldCapture(
       // all lifecycle effect tags.
       sourceFiber.flags &= ~(LifecycleEffectMask | Incomplete);
 
-      if (supportsPersistence && enablePersistentOffscreenHostContainer) {
-        // Another legacy Suspense quirk. In persistent mode, if this is the
-        // initial mount, override the props of the host container to hide
-        // its contents.
-        const currentSuspenseBoundary = suspenseBoundary.alternate;
-        if (currentSuspenseBoundary === null) {
-          const offscreenFiber: Fiber = (suspenseBoundary.child: any);
-          const offscreenContainer = offscreenFiber.child;
-          if (offscreenContainer !== null) {
-            const children = offscreenContainer.memoizedProps.children;
-            const containerProps = getOffscreenContainerProps(
-              'hidden',
-              children,
-            );
-            offscreenContainer.pendingProps = containerProps;
-            offscreenContainer.memoizedProps = containerProps;
-          }
-        }
-      }
-
       if (sourceFiber.tag === ClassComponent) {
         const currentSourceFiber = sourceFiber.alternate;
         if (currentSourceFiber === null) {
diff --git a/packages/react-reconciler/src/ReactFiberThrow.old.js b/packages/react-reconciler/src/ReactFiberThrow.old.js
index a8e75e9ce661..66f91a69d343 100644
--- a/packages/react-reconciler/src/ReactFiberThrow.old.js
+++ b/packages/react-reconciler/src/ReactFiberThrow.old.js
@@ -34,17 +34,12 @@ import {
   ForceUpdateForLegacySuspense,
   ForceClientRender,
 } from './ReactFiberFlags';
-import {
-  supportsPersistence,
-  getOffscreenContainerProps,
-} from './ReactFiberHostConfig';
 import {shouldCaptureSuspense} from './ReactFiberSuspenseComponent.old';
 import {NoMode, ConcurrentMode, DebugTracingMode} from './ReactTypeOfMode';
 import {
   enableDebugTracing,
   enableLazyContextPropagation,
   enableUpdaterTracking,
-  enablePersistentOffscreenHostContainer,
 } from 'shared/ReactFeatureFlags';
 import {createCapturedValue} from './ReactCapturedValue';
 import {
@@ -336,26 +331,6 @@ function markSuspenseBoundaryShouldCapture(
       // all lifecycle effect tags.
       sourceFiber.flags &= ~(LifecycleEffectMask | Incomplete);
 
-      if (supportsPersistence && enablePersistentOffscreenHostContainer) {
-        // Another legacy Suspense quirk. In persistent mode, if this is the
-        // initial mount, override the props of the host container to hide
-        // its contents.
-        const currentSuspenseBoundary = suspenseBoundary.alternate;
-        if (currentSuspenseBoundary === null) {
-          const offscreenFiber: Fiber = (suspenseBoundary.child: any);
-          const offscreenContainer = offscreenFiber.child;
-          if (offscreenContainer !== null) {
-            const children = offscreenContainer.memoizedProps.children;
-            const containerProps = getOffscreenContainerProps(
-              'hidden',
-              children,
-            );
-            offscreenContainer.pendingProps = containerProps;
-            offscreenContainer.memoizedProps = containerProps;
-          }
-        }
-      }
-
       if (sourceFiber.tag === ClassComponent) {
         const currentSourceFiber = sourceFiber.alternate;
         if (currentSourceFiber === null) {
diff --git a/packages/react-reconciler/src/forks/ReactFiberHostConfig.custom.js b/packages/react-reconciler/src/forks/ReactFiberHostConfig.custom.js
index f2705b7b1df4..e8856f00ae40 100644
--- a/packages/react-reconciler/src/forks/ReactFiberHostConfig.custom.js
+++ b/packages/react-reconciler/src/forks/ReactFiberHostConfig.custom.js
@@ -121,10 +121,6 @@ export const appendChildToContainerChildSet =
 export const finalizeContainerChildren =
   $$$hostConfig.finalizeContainerChildren;
 export const replaceContainerChildren = $$$hostConfig.replaceContainerChildren;
-export const getOffscreenContainerType =
-  $$$hostConfig.getOffscreenContainerType;
-export const getOffscreenContainerProps =
-  $$$hostConfig.getOffscreenContainerProps;
 export const cloneHiddenInstance = $$$hostConfig.cloneHiddenInstance;
 export const cloneHiddenTextInstance = $$$hostConfig.cloneHiddenTextInstance;
 
diff --git a/packages/shared/ReactFeatureFlags.js b/packages/shared/ReactFeatureFlags.js
index 218a3514f0f3..7b76a1f7524c 100644
--- a/packages/shared/ReactFeatureFlags.js
+++ b/packages/shared/ReactFeatureFlags.js
@@ -16,7 +16,6 @@
 export const warnAboutDeprecatedLifecycles = true;
 export const enableComponentStackLocations = true;
 export const disableSchedulerTimeoutBasedOnReactExpirationTime = false;
-export const enablePersistentOffscreenHostContainer = false;
 
 // -----------------------------------------------------------------------------
 // Land or remove (moderate effort)
diff --git a/packages/shared/forks/ReactFeatureFlags.native-fb-dynamic.js b/packages/shared/forks/ReactFeatureFlags.native-fb-dynamic.js
index 63f75e83b765..7138679c536e 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-fb-dynamic.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-fb-dynamic.js
@@ -7,8 +7,10 @@
  * @flow strict
  */
 
-import typeof * as ExportsType from './ReactFeatureFlags.native-fb-dynamic';
-import typeof * as DynamicFlagsType from 'ReactNativeInternalFeatureFlags';
+// NOTE: There are no flags, currently. Uncomment the stuff below if we add one.
+
+// import typeof * as ExportsType from './ReactFeatureFlags.native-fb-dynamic';
+// import typeof * as DynamicFlagsType from 'ReactNativeInternalFeatureFlags';
 
 // In xplat, these flags are controlled by GKs. Because most GKs have some
 // population running in either mode, we should run our tests that way, too,
@@ -20,10 +22,8 @@ import typeof * as DynamicFlagsType from 'ReactNativeInternalFeatureFlags';
 // flag here but it won't be set to `true` in any of our test runs. Need to
 // update the test configuration.
 
-export const enablePersistentOffscreenHostContainer = __VARIANT__;
-
-// Flow magic to verify the exports of this file match the original version.
-// eslint-disable-next-line no-unused-vars
-type Check<_X, Y: _X, X: Y = _X> = null;
-// eslint-disable-next-line no-unused-expressions
-(null: Check<ExportsType, DynamicFlagsType>);
+// // Flow magic to verify the exports of this file match the original version.
+// // eslint-disable-next-line no-unused-vars
+// type Check<_X, Y: _X, X: Y = _X> = null;
+// // eslint-disable-next-line no-unused-expressions
+// (null: Check<ExportsType, DynamicFlagsType>);
diff --git a/packages/shared/forks/ReactFeatureFlags.native-fb.js b/packages/shared/forks/ReactFeatureFlags.native-fb.js
index 6baef5948997..ea80fba1da24 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-fb.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-fb.js
@@ -10,13 +10,14 @@
 import typeof * as FeatureFlagsType from 'shared/ReactFeatureFlags';
 import typeof * as ExportsType from './ReactFeatureFlags.native-fb';
 
+// NOTE: There are no flags, currently. Uncomment the stuff below if we add one.
 // Re-export dynamic flags from the internal module. Intentionally using *
 // because this import is compiled to a `require` call.
-import * as dynamicFlags from 'ReactNativeInternalFeatureFlags';
+// import * as dynamicFlags from 'ReactNativeInternalFeatureFlags';
 
 // We destructure each value before re-exporting to avoid a dynamic look-up on
 // the exports object every time a flag is read.
-export const {enablePersistentOffscreenHostContainer} = dynamicFlags;
+// export const {} = dynamicFlags;
 
 // The rest of the flags are static for better dead code elimination.
 export const enableDebugTracing = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.native-oss.js b/packages/shared/forks/ReactFeatureFlags.native-oss.js
index e9398deee80d..9a5c2bca40a7 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-oss.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-oss.js
@@ -62,7 +62,6 @@ export const enableLazyContextPropagation = false;
 export const enableLegacyHidden = false;
 export const enableSyncDefaultUpdates = true;
 export const allowConcurrentByDefault = false;
-export const enablePersistentOffscreenHostContainer = false;
 export const enableCustomElementPropertySupport = false;
 
 export const consoleManagedByDevToolsDuringStrictMode = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.js
index c3ca7f565c73..157fda232ed3 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.js
@@ -62,7 +62,6 @@ export const enableLazyContextPropagation = false;
 export const enableLegacyHidden = false;
 export const enableSyncDefaultUpdates = true;
 export const allowConcurrentByDefault = false;
-export const enablePersistentOffscreenHostContainer = false;
 export const enableCustomElementPropertySupport = false;
 
 export const consoleManagedByDevToolsDuringStrictMode = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js
index d186c1852e6b..0a770e1438a8 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js
@@ -61,7 +61,6 @@ export const enableLazyContextPropagation = false;
 export const enableLegacyHidden = false;
 export const enableSyncDefaultUpdates = true;
 export const allowConcurrentByDefault = true;
-export const enablePersistentOffscreenHostContainer = false;
 
 export const consoleManagedByDevToolsDuringStrictMode = false;
 export const enableServerContext = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
index e258b155c2c1..157f9d6a4152 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
@@ -62,7 +62,6 @@ export const enableLazyContextPropagation = false;
 export const enableLegacyHidden = false;
 export const enableSyncDefaultUpdates = true;
 export const allowConcurrentByDefault = true;
-export const enablePersistentOffscreenHostContainer = false;
 export const enableCustomElementPropertySupport = false;
 
 export const consoleManagedByDevToolsDuringStrictMode = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.testing.js b/packages/shared/forks/ReactFeatureFlags.testing.js
index d173aaa1b30a..072c58b5c8ec 100644
--- a/packages/shared/forks/ReactFeatureFlags.testing.js
+++ b/packages/shared/forks/ReactFeatureFlags.testing.js
@@ -62,7 +62,6 @@ export const enableLazyContextPropagation = false;
 export const enableLegacyHidden = false;
 export const enableSyncDefaultUpdates = true;
 export const allowConcurrentByDefault = false;
-export const enablePersistentOffscreenHostContainer = false;
 export const enableCustomElementPropertySupport = false;
 
 export const consoleManagedByDevToolsDuringStrictMode = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.testing.www.js b/packages/shared/forks/ReactFeatureFlags.testing.www.js
index c2842d955938..a607e3ea7f71 100644
--- a/packages/shared/forks/ReactFeatureFlags.testing.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.testing.www.js
@@ -62,7 +62,6 @@ export const enableLazyContextPropagation = false;
 export const enableLegacyHidden = false;
 export const enableSyncDefaultUpdates = true;
 export const allowConcurrentByDefault = true;
-export const enablePersistentOffscreenHostContainer = false;
 export const enableCustomElementPropertySupport = false;
 
 export const consoleManagedByDevToolsDuringStrictMode = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.www-dynamic.js b/packages/shared/forks/ReactFeatureFlags.www-dynamic.js
index 253cb58a2d1f..7a89e41ad54f 100644
--- a/packages/shared/forks/ReactFeatureFlags.www-dynamic.js
+++ b/packages/shared/forks/ReactFeatureFlags.www-dynamic.js
@@ -60,6 +60,5 @@ export const disableNativeComponentFrames = false;
 export const createRootStrictEffectsByDefault = false;
 export const enableStrictEffects = false;
 export const allowConcurrentByDefault = true;
-export const enablePersistentOffscreenHostContainer = false;
 // You probably *don't* want to add more hardcoded ones.
 // Instead, try to add them above with the __VARIANT__ value.
diff --git a/packages/shared/forks/ReactFeatureFlags.www.js b/packages/shared/forks/ReactFeatureFlags.www.js
index 5a8f89bae840..a1932e21c4e1 100644
--- a/packages/shared/forks/ReactFeatureFlags.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.www.js
@@ -99,8 +99,6 @@ export const allowConcurrentByDefault = true;
 
 export const deletedTreeCleanUpLevel = 3;
 
-export const enablePersistentOffscreenHostContainer = false;
-
 export const consoleManagedByDevToolsDuringStrictMode = true;
 export const enableServerContext = true;
 
diff --git a/scripts/flow/xplat.js b/scripts/flow/xplat.js
index c013af3e125d..45c12d2a6f60 100644
--- a/scripts/flow/xplat.js
+++ b/scripts/flow/xplat.js
@@ -8,5 +8,4 @@
  */
 
 declare module 'ReactNativeInternalFeatureFlags' {
-  declare export var enablePersistentOffscreenHostContainer: boolean;
 }