RN: Migrate VirtualView to Feature Flags (facebook#51233)

Summary:
Pull Request resolved: facebook#51233

Migrates internal operational and experimental feature flags to React Native's feature flag system, in order to simplify integration of other infrastructure features (e.g. Fantom).

Changelog:
[Internal]

Reviewed By: lunaleaps

Differential Revision: D74534921

fbshipit-source-id: 1559cba4f208a554bb043a203f331062036c60de

Author: yungsters

packages/react-native/scripts/featureflags/ReactNativeFeatureFlags.config.js

@@ -610,6 +610,27 @@ const definitions: FeatureFlagDefinitions = {
       },
       ossReleaseStage: 'none',
     },
+    enableVirtualViewDebugFeatures: {
+      defaultValue: false,
+      metadata: {
+        description:
+          'Enables VirtualView debug features such as logging and overlays.',
+        expectedReleaseValue: false,
+        purpose: 'operational',
+      },
+      ossReleaseStage: 'none',
+    },
+    enableVirtualViewDoubleStateHidden: {
+      defaultValue: false,
+      metadata: {
+        dateAdded: '2025-05-10',
+        description:
+          'Enables a VirtualView workaround that triggers a second state update when changing to hidden mode.',
+        expectedReleaseValue: false,
+        purpose: 'experimentation',
+      },
+      ossReleaseStage: 'none',
+    },
     fixVirtualizeListCollapseWindowSize: {
       defaultValue: false,
       metadata: {

packages/react-native/src/private/featureflags/ReactNativeFeatureFlags.js

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<73bd98850713966c32d122c3d3283df9>>
+ * @generated SignedSource<<24076ce2a95804d6dda128740cbbae8f>>
  * @flow strict
  */
 
@@ -33,6 +33,8 @@ export type ReactNativeFeatureFlagsJsOnly = $ReadOnly<{
   avoidStateUpdateInAnimatedPropsMemo: Getter<boolean>,
   disableInteractionManager: Getter<boolean>,
   enableAccessToHostTreeInFabric: Getter<boolean>,
+  enableVirtualViewDebugFeatures: Getter<boolean>,
+  enableVirtualViewDoubleStateHidden: Getter<boolean>,
   fixVirtualizeListCollapseWindowSize: Getter<boolean>,
   isLayoutAnimationEnabled: Getter<boolean>,
   scheduleAnimatedCleanupInMicrotask: Getter<boolean>,
@@ -127,6 +129,16 @@ export const disableInteractionManager: Getter<boolean> = createJavaScriptFlagGe
  */
 export const enableAccessToHostTreeInFabric: Getter<boolean> = createJavaScriptFlagGetter('enableAccessToHostTreeInFabric', false);
 
+/**
+ * Enables VirtualView debug features such as logging and overlays.
+ */
+export const enableVirtualViewDebugFeatures: Getter<boolean> = createJavaScriptFlagGetter('enableVirtualViewDebugFeatures', false);
+
+/**
+ * Enables a VirtualView workaround that triggers a second state update when changing to hidden mode.
+ */
+export const enableVirtualViewDoubleStateHidden: Getter<boolean> = createJavaScriptFlagGetter('enableVirtualViewDoubleStateHidden', false);
+
 /**
  * Fixing an edge case where the current window size is not properly calculated with fast scrolling. Window size collapsed to 1 element even if windowSize more than the current amount of elements
  */