unstable portal container for react-aria (#6297)

Co-authored-by: Reid Barber <reid@reidbarber.com>

Author: snowystinger

packages/@react-aria/overlays/src/Overlay.tsx

@@ -16,6 +16,7 @@ import React, {ReactNode, useContext, useMemo, useState} from 'react';
 import ReactDOM from 'react-dom';
 import {useIsSSR} from '@react-aria/ssr';
 import {useLayoutEffect} from '@react-aria/utils';
+import {useUNSTABLE_PortalContext} from './PortalProvider';
 
 export interface OverlayProps {
   /**
@@ -50,6 +51,11 @@ export function Overlay(props: OverlayProps) {
   let [contain, setContain] = useState(false);
   let contextValue = useMemo(() => ({contain, setContain}), [contain, setContain]);
 
+  let {getContainer} = useUNSTABLE_PortalContext();
+  if  (!props.portalContainer && getContainer) {
+    portalContainer = getContainer();
+  }
+
   if (!portalContainer) {
     return null;
   }

packages/@react-spectrum/overlays/src/Overlay.tsx

@@ -15,7 +15,7 @@ import {OpenTransition} from './OpenTransition';
 import {OverlayProps} from '@react-types/overlays';
 import {Provider} from '@react-spectrum/provider';
 import React, {useCallback, useState} from 'react';
-import {Overlay as ReactAriaOverlay, useUNSTABLE_PortalContext} from '@react-aria/overlays';
+import {Overlay as ReactAriaOverlay} from '@react-aria/overlays';
 
 function Overlay(props: OverlayProps, ref: DOMRef<HTMLDivElement>) {
   let {
@@ -32,11 +32,6 @@ function Overlay(props: OverlayProps, ref: DOMRef<HTMLDivElement>) {
     nodeRef
   } = props;
 
-  let {getContainer} = useUNSTABLE_PortalContext();
-  if  (!container && getContainer) {
-    container = getContainer();
-  }
-
   let [exited, setExited] = useState(!isOpen);
 
   let handleEntered = useCallback(() => {