s/getRootNode/ownerDocument (facebook#28412)

getRootNode isn't always available, use ownerDocument instead

packages/react-dom-bindings/src/client/ReactDOMComponent.js

@@ -2273,7 +2273,7 @@ function diffHydratedCustomComponent(
 // as a shared module for that reason.
 const EXPECTED_FORM_ACTION_URL =
   // eslint-disable-next-line no-script-url
-  "javascript:throw new Error('A React form was unexpectedly submitted.')";
+  "javascript:throw new Error('React form unexpectedly submitted.')";
 
 function diffHydratedGenericElement(
   domElement: Element,

packages/react-dom-bindings/src/events/ReactDOMEventReplaying.js

@@ -537,7 +537,8 @@ export function retryIfBlockedOn(
 
   if (enableFormActions) {
     // Check the document if there are any queued form actions.
-    const root = unblocked.getRootNode();
+    // If there's no ownerDocument, then this is the document.
+    const root = unblocked.ownerDocument || unblocked;
     const formReplayingQueue: void | FormReplayingQueue = (root: any)
       .$$reactFormReplay;
     if (formReplayingQueue != null) {

packages/react-dom-bindings/src/server/ReactFizzConfigDOM.js

@@ -1015,7 +1015,7 @@ function makeFormFieldPrefix(resumableState: ResumableState): string {
 const actionJavaScriptURL = stringToPrecomputedChunk(
   escapeTextForBrowser(
     // eslint-disable-next-line no-script-url
-    "javascript:throw new Error('A React form was unexpectedly submitted.')",
+    "javascript:throw new Error('React form unexpectedly submitted.')",
   ),
 );
 

packages/react-dom-bindings/src/server/fizz-instruction-set/ReactDOMFizzInstructionSetShared.js

@@ -131,7 +131,7 @@ export function completeSegment(containerID, placeholderID) {
 // as a shared module for that reason.
 const EXPECTED_FORM_ACTION_URL =
   // eslint-disable-next-line no-script-url
-  "javascript:throw new Error('A React form was unexpectedly submitted.')";
+  "javascript:throw new Error('React form unexpectedly submitted.')";
 
 export function listenToFormSubmissionsForReplaying() {
   // A global replay queue ensures actions are replayed in order.
@@ -196,9 +196,8 @@ export function listenToFormSubmissionsForReplaying() {
     // javascript: URL placeholder value. So we might not be the first to declare it.
     // We attach it to the form's root node, which is the shared environment context
     // where we preserve sequencing and where we'll pick it up from during hydration.
-    // In practice, this is just the same as document but we might support shadow trees
-    // in the future.
-    const root = form.getRootNode();
+    // If there's no ownerDocument, then this is the document.
+    const root = form.ownerDocument || form;
     (root['$$reactFormReplay'] = root['$$reactFormReplay'] || []).push(
       form,
       submitter,