Rollout enablePersistedModeClonedFlag (facebook#34520)

## Summary

Experimentation has completed for this at Meta and we've observed
positive impact on key React Native surfaces.

## How did you test this change?

yarn flow fabric

Author: javache

packages/react-native-renderer/src/__tests__/ReactFabric-test.internal.js

@@ -287,7 +287,6 @@ describe('ReactFabric', () => {
     expect(nativeFabricUIManager.completeRoot).toBeCalled();
   });
 
-  // @gate enablePersistedModeClonedFlag
   it('should not clone nodes when layout effects are used', async () => {
     const View = createReactNativeComponentClass('RCTView', () => ({
       validAttributes: {foo: true},
@@ -305,6 +304,8 @@ describe('ReactFabric', () => {
           <ComponentWithEffect />
         </View>,
         11,
+        null,
+        true,
       ),
     );
     expect(nativeFabricUIManager.completeRoot).toBeCalled();
@@ -316,6 +317,8 @@ describe('ReactFabric', () => {
           <ComponentWithEffect />
         </View>,
         11,
+        null,
+        true,
       ),
     );
     expect(nativeFabricUIManager.cloneNode).not.toBeCalled();
@@ -327,7 +330,6 @@ describe('ReactFabric', () => {
     expect(nativeFabricUIManager.completeRoot).not.toBeCalled();
   });
 
-  // @gate enablePersistedModeClonedFlag
   it('should not clone nodes when insertion effects are used', async () => {
     const View = createReactNativeComponentClass('RCTView', () => ({
       validAttributes: {foo: true},
@@ -345,6 +347,8 @@ describe('ReactFabric', () => {
           <ComponentWithRef />
         </View>,
         11,
+        null,
+        true,
       ),
     );
     expect(nativeFabricUIManager.completeRoot).toBeCalled();
@@ -356,6 +360,8 @@ describe('ReactFabric', () => {
           <ComponentWithRef />
         </View>,
         11,
+        null,
+        true,
       ),
     );
     expect(nativeFabricUIManager.cloneNode).not.toBeCalled();
@@ -367,7 +373,6 @@ describe('ReactFabric', () => {
     expect(nativeFabricUIManager.completeRoot).not.toBeCalled();
   });
 
-  // @gate enablePersistedModeClonedFlag
   it('should not clone nodes when useImperativeHandle is used', async () => {
     const View = createReactNativeComponentClass('RCTView', () => ({
       validAttributes: {foo: true},
@@ -387,6 +392,8 @@ describe('ReactFabric', () => {
           <ComponentWithImperativeHandle ref={ref} />
         </View>,
         11,
+        null,
+        true,
       ),
     );
     expect(nativeFabricUIManager.completeRoot).toBeCalled();
@@ -399,6 +406,8 @@ describe('ReactFabric', () => {
           <ComponentWithImperativeHandle ref={ref} />
         </View>,
         11,
+        null,
+        true,
       ),
     );
     expect(nativeFabricUIManager.cloneNode).not.toBeCalled();

packages/react-reconciler/src/ReactFiberCommitWork.js

@@ -48,7 +48,6 @@ import {
   alwaysThrottleRetries,
   enableCreateEventHandleAPI,
   enableHiddenSubtreeInsertionEffectCleanup,
-  enablePersistedModeClonedFlag,
   enableProfilerTimer,
   enableProfilerCommitHooks,
   enableSuspenseCallback,
@@ -1969,10 +1968,7 @@ function recursivelyTraverseMutationEffects(
     }
   }
 
-  if (
-    parentFiber.subtreeFlags &
-    (enablePersistedModeClonedFlag ? MutationMask | Cloned : MutationMask)
-  ) {
+  if (parentFiber.subtreeFlags & (MutationMask | Cloned)) {
     let child = parentFiber.child;
     while (child !== null) {
       commitMutationEffectsOnFiber(child, root, lanes);

packages/react-reconciler/src/ReactFiberCompleteWork.js

@@ -35,7 +35,6 @@ import {
   enableLegacyHidden,
   enableSuspenseCallback,
   enableScopeAPI,
-  enablePersistedModeClonedFlag,
   enableProfilerTimer,
   enableTransitionTracing,
   passChildrenWhenCloningPersistedNodes,
@@ -92,7 +91,6 @@ import {
   Snapshot,
   ChildDeletion,
   StaticMask,
-  MutationMask,
   Passive,
   ForceClientRender,
   MaySuspendCommit,
@@ -205,7 +203,7 @@ function markUpdate(workInProgress: Fiber) {
  * it received an update that requires a clone of the tree above.
  */
 function markCloned(workInProgress: Fiber) {
-  if (supportsPersistence && enablePersistedModeClonedFlag) {
+  if (supportsPersistence) {
     workInProgress.flags |= Cloned;
   }
 }
@@ -227,9 +225,7 @@ function doesRequireClone(current: null | Fiber, completedWork: Fiber) {
   // then we only have to check the `completedWork.subtreeFlags`.
   let child = completedWork.child;
   while (child !== null) {
-    const checkedFlags = enablePersistedModeClonedFlag
-      ? Cloned | Visibility | Placement | ChildDeletion
-      : MutationMask;
+    const checkedFlags = Cloned | Visibility | Placement | ChildDeletion;
     if (
       (child.flags & checkedFlags) !== NoFlags ||
       (child.subtreeFlags & checkedFlags) !== NoFlags
@@ -526,16 +522,9 @@ function updateHostComponent(
       markUpdate(workInProgress);
     }
     workInProgress.stateNode = newInstance;
-    if (!requiresClone) {
-      if (!enablePersistedModeClonedFlag) {
-        // If there are no other effects in this tree, we need to flag this node as having one.
-        // Even though we're not going to use it for anything.
-        // Otherwise parents won't know that there are new children to propagate upwards.
-        markUpdate(workInProgress);
-      }
-    } else if (
-      !passChildrenWhenCloningPersistedNodes ||
-      hasOffscreenComponentChild
+    if (
+      requiresClone &&
+      (!passChildrenWhenCloningPersistedNodes || hasOffscreenComponentChild)
     ) {
       // If children have changed, we have to add them all to the set.
       appendAllChildren(
@@ -693,11 +682,6 @@ function updateHostText(
         currentHostContext,
         workInProgress,
       );
-      if (!enablePersistedModeClonedFlag) {
-        // We'll have to mark it as having an effect, even though we won't use the effect for anything.
-        // This lets the parents know that at least one of their children has changed.
-        markUpdate(workInProgress);
-      }
     } else {
       workInProgress.stateNode = current.stateNode;
     }

packages/shared/ReactFeatureFlags.js

@@ -129,12 +129,6 @@ export const alwaysThrottleRetries: boolean = true;
 
 export const passChildrenWhenCloningPersistedNodes: boolean = false;
 
-/**
- * Enables a new Fiber flag used in persisted mode to reduce the number
- * of cloned host components.
- */
-export const enablePersistedModeClonedFlag: boolean = false;
-
 export const enableEagerAlternateStateNodeCleanup: boolean = true;
 
 /**

packages/shared/forks/ReactFeatureFlags.native-fb-dynamic.js

@@ -20,7 +20,6 @@
 export const alwaysThrottleRetries = __VARIANT__;
 export const enableObjectFiber = __VARIANT__;
 export const enableHiddenSubtreeInsertionEffectCleanup = __VARIANT__;
-export const enablePersistedModeClonedFlag = __VARIANT__;
 export const enableEagerAlternateStateNodeCleanup = __VARIANT__;
 export const passChildrenWhenCloningPersistedNodes = __VARIANT__;
 export const renameElementSymbol = __VARIANT__;

packages/shared/forks/ReactFeatureFlags.native-fb.js

@@ -22,7 +22,6 @@ export const {
   alwaysThrottleRetries,
   enableHiddenSubtreeInsertionEffectCleanup,
   enableObjectFiber,
-  enablePersistedModeClonedFlag,
   enableEagerAlternateStateNodeCleanup,
   passChildrenWhenCloningPersistedNodes,
   renameElementSymbol,

packages/shared/forks/ReactFeatureFlags.native-oss.js

@@ -38,7 +38,6 @@ export const enableLegacyFBSupport: boolean = false;
 export const enableLegacyHidden: boolean = false;
 export const enableNoCloningMemoCache: boolean = false;
 export const enableObjectFiber: boolean = false;
-export const enablePersistedModeClonedFlag: boolean = false;
 export const enablePostpone: boolean = false;
 export const enableReactTestRendererWarning: boolean = false;
 export const enableRetryLaneExpiration: boolean = false;

packages/shared/forks/ReactFeatureFlags.test-renderer.js

@@ -53,7 +53,6 @@ export const enableFizzExternalRuntime: boolean = true;
 export const alwaysThrottleRetries: boolean = true;
 
 export const passChildrenWhenCloningPersistedNodes: boolean = false;
-export const enablePersistedModeClonedFlag: boolean = false;
 export const disableClientCache: boolean = true;
 
 export const enableInfiniteRenderLoopDetection: boolean = false;

packages/shared/forks/ReactFeatureFlags.test-renderer.native-fb.js

@@ -33,7 +33,6 @@ export const enableLegacyFBSupport = false;
 export const enableLegacyHidden = false;
 export const enableNoCloningMemoCache = false;
 export const enableObjectFiber = false;
-export const enablePersistedModeClonedFlag = false;
 export const enablePostpone = false;
 export const enableProfilerCommitHooks = __PROFILE__;
 export const enableProfilerNestedUpdatePhase = __PROFILE__;

packages/shared/forks/ReactFeatureFlags.test-renderer.www.js

@@ -54,7 +54,6 @@ export const enableFizzExternalRuntime: boolean = false;
 export const alwaysThrottleRetries: boolean = true;
 
 export const passChildrenWhenCloningPersistedNodes: boolean = false;
-export const enablePersistedModeClonedFlag: boolean = false;
 export const disableClientCache: boolean = true;
 
 export const enableInfiniteRenderLoopDetection: boolean = false;