[flags] enable opt-in for enableDefaultTransitionIndicator (#34373)

So we can test the feature.

Author: rickhanlonii

packages/react-dom/src/client/ReactDOMRootFB.js

@@ -126,6 +126,7 @@ function wwwOnCaughtError(
 
   defaultOnCaughtError(error, errorInfo);
 }
+const noopOnDefaultTransitionIndicator = noop;
 
 export function createRoot(
   container: Element | Document | DocumentFragment,
@@ -137,6 +138,7 @@ export function createRoot(
       ({
         onUncaughtError: wwwOnUncaughtError,
         onCaughtError: wwwOnCaughtError,
+        onDefaultTransitionIndicator: noopOnDefaultTransitionIndicator,
       }: any),
       options,
     ),
@@ -155,6 +157,7 @@ export function hydrateRoot(
       ({
         onUncaughtError: wwwOnUncaughtError,
         onCaughtError: wwwOnCaughtError,
+        onDefaultTransitionIndicator: noopOnDefaultTransitionIndicator,
       }: any),
       options,
     ),
@@ -211,7 +214,6 @@ function getReactRootElementInContainer(container: any) {
 // This isn't reachable because onRecoverableError isn't called in the
 // legacy API.
 const noopOnRecoverableError = noop;
-const noopOnDefaultTransitionIndicator = noop;
 
 function legacyCreateRootFromDOMContainer(
   container: Container,

packages/react-native-renderer/src/ReactFabric.js

@@ -46,7 +46,10 @@ import {
   createPublicRootInstance,
   type PublicRootInstance,
 } from 'react-native/Libraries/ReactPrivate/ReactNativePrivateInterface';
-import {disableLegacyMode} from 'shared/ReactFeatureFlags';
+import {
+  disableLegacyMode,
+  enableDefaultTransitionIndicator,
+} from 'shared/ReactFeatureFlags';
 
 if (typeof ReactFiberErrorDialog.showErrorDialog !== 'function') {
   throw new Error(
@@ -132,6 +135,12 @@ function render(
     if (options && options.onRecoverableError !== undefined) {
       onRecoverableError = options.onRecoverableError;
     }
+    let onDefaultTransitionIndicator = nativeOnDefaultTransitionIndicator;
+    if (enableDefaultTransitionIndicator) {
+      if (options && options.onDefaultTransitionIndicator !== undefined) {
+        onDefaultTransitionIndicator = options.onDefaultTransitionIndicator;
+      }
+    }
 
     const publicRootInstance = createPublicRootInstance(containerTag);
     const rootInstance = {
@@ -151,7 +160,7 @@ function render(
       onUncaughtError,
       onCaughtError,
       onRecoverableError,
-      nativeOnDefaultTransitionIndicator,
+      onDefaultTransitionIndicator,
       null,
     );
 

packages/react-native-renderer/src/ReactNativeTypes.js

@@ -134,6 +134,7 @@ export type RenderRootOptions = {
     error: mixed,
     errorInfo: {+componentStack?: ?string},
   ) => void,
+  onDefaultTransitionIndicator?: () => void | (() => void),
 };
 
 /**

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

@@ -79,7 +79,7 @@ export const enableSuspenseyImages: boolean = false;
 export const enableFizzBlockingRender: boolean = true;
 export const enableSrcObject: boolean = false;
 export const enableHydrationChangeEvent: boolean = true;
-export const enableDefaultTransitionIndicator: boolean = false;
+export const enableDefaultTransitionIndicator: boolean = true;
 export const ownerStackLimit = 1e4;
 export const enableComponentPerformanceTrack: boolean =
   __PROFILE__ && dynamicFlags.enableComponentPerformanceTrack;

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

@@ -66,7 +66,7 @@ export const enableSuspenseyImages = false;
 export const enableFizzBlockingRender = true;
 export const enableSrcObject = false;
 export const enableHydrationChangeEvent = false;
-export const enableDefaultTransitionIndicator = false;
+export const enableDefaultTransitionIndicator = true;
 export const enableFragmentRefs = false;
 export const enableFragmentRefsScrollIntoView = false;
 export const ownerStackLimit = 1e4;

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

@@ -79,7 +79,7 @@ export const enableSuspenseyImages: boolean = false;
 export const enableFizzBlockingRender: boolean = true;
 export const enableSrcObject: boolean = false;
 export const enableHydrationChangeEvent: boolean = false;
-export const enableDefaultTransitionIndicator: boolean = false;
+export const enableDefaultTransitionIndicator: boolean = true;
 
 export const enableFragmentRefs: boolean = false;
 export const enableFragmentRefsScrollIntoView: boolean = false;

packages/shared/forks/ReactFeatureFlags.www.js

@@ -109,7 +109,7 @@ export const enableSuspenseyImages: boolean = false;
 export const enableFizzBlockingRender: boolean = true;
 export const enableSrcObject: boolean = false;
 export const enableHydrationChangeEvent: boolean = false;
-export const enableDefaultTransitionIndicator: boolean = false;
+export const enableDefaultTransitionIndicator: boolean = true;
 
 export const ownerStackLimit = 1e4;