add offscreen state node (#24026)

Add state node on Offscreen fibers with id (in preparation for transition tracing)

Author: lunaruan

packages/react-reconciler/src/ReactFiber.new.js

@@ -15,7 +15,10 @@ import type {WorkTag} from './ReactWorkTags';
 import type {TypeOfMode} from './ReactTypeOfMode';
 import type {Lanes} from './ReactFiberLane.new';
 import type {SuspenseInstance, Props} from './ReactFiberHostConfig';
-import type {OffscreenProps} from './ReactFiberOffscreenComponent';
+import type {
+  OffscreenProps,
+  OffscreenInstance,
+} from './ReactFiberOffscreenComponent';
 
 import {
   createRootStrictEffectsByDefault,
@@ -735,6 +738,8 @@ export function createFiberFromOffscreen(
   const fiber = createFiber(OffscreenComponent, pendingProps, key, mode);
   fiber.elementType = REACT_OFFSCREEN_TYPE;
   fiber.lanes = lanes;
+  const primaryChildInstance: OffscreenInstance = {};
+  fiber.stateNode = primaryChildInstance;
   return fiber;
 }
 

packages/react-reconciler/src/ReactFiber.old.js

@@ -15,7 +15,10 @@ import type {WorkTag} from './ReactWorkTags';
 import type {TypeOfMode} from './ReactTypeOfMode';
 import type {Lanes} from './ReactFiberLane.old';
 import type {SuspenseInstance, Props} from './ReactFiberHostConfig';
-import type {OffscreenProps} from './ReactFiberOffscreenComponent';
+import type {
+  OffscreenProps,
+  OffscreenInstance,
+} from './ReactFiberOffscreenComponent';
 
 import {
   createRootStrictEffectsByDefault,
@@ -735,6 +738,8 @@ export function createFiberFromOffscreen(
   const fiber = createFiber(OffscreenComponent, pendingProps, key, mode);
   fiber.elementType = REACT_OFFSCREEN_TYPE;
   fiber.lanes = lanes;
+  const primaryChildInstance: OffscreenInstance = {};
+  fiber.stateNode = primaryChildInstance;
   return fiber;
 }
 

packages/react-reconciler/src/ReactFiberOffscreenComponent.js

@@ -31,3 +31,5 @@ export type OffscreenState = {|
   baseLanes: Lanes,
   cachePool: SpawnedCachePool | null,
 |};
+
+export type OffscreenInstance = {};