Remove useMutableSource (#27011)

## Summary

This PR cleans up `useMutableSource`. This has been blocked by a
remaining dependency internally at Meta, but that has now been deleted.

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Explain the **motivation** for making this change. What existing problem
does the pull request solve?
-->

## How did you test this change?

```
yarn flow
yarn lint
yarn test --prod
```

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packages/react-debug-tools/src/ReactDebugHooks.js

@@ -8,9 +8,6 @@
  */
 
 import type {
-  MutableSource,
-  MutableSourceGetSnapshotFn,
-  MutableSourceSubscribeFn,
   ReactContext,
   ReactProviderType,
   StartTransitionOptions,
@@ -273,23 +270,6 @@ function useMemo<T>(
   return value;
 }
 
-function useMutableSource<Source, Snapshot>(
-  source: MutableSource<Source>,
-  getSnapshot: MutableSourceGetSnapshotFn<Source, Snapshot>,
-  subscribe: MutableSourceSubscribeFn<Source, Snapshot>,
-): Snapshot {
-  // useMutableSource() composes multiple hooks internally.
-  // Advance the current hook index the same number of times
-  // so that subsequent hooks have the right memoized state.
-  nextHook(); // MutableSource
-  nextHook(); // State
-  nextHook(); // Effect
-  nextHook(); // Effect
-  const value = getSnapshot(source._source);
-  hookLog.push({primitive: 'MutableSource', stackError: new Error(), value});
-  return value;
-}
-
 function useSyncExternalStore<T>(
   subscribe: (() => void) => () => void,
   getSnapshot: () => T,
@@ -396,7 +376,6 @@ const Dispatcher: DispatcherType = {
   useRef,
   useState,
   useTransition,
-  useMutableSource,
   useSyncExternalStore,
   useDeferredValue,
   useId,

packages/react-debug-tools/src/__tests__/ReactHooksInspectionIntegration-test.js

@@ -1036,52 +1036,6 @@ describe('ReactHooksInspectionIntegration', () => {
     ]);
   });
 
-  // @gate enableUseMutableSource
-  it('should support composite useMutableSource hook', () => {
-    const createMutableSource =
-      React.createMutableSource || React.unstable_createMutableSource;
-    const useMutableSource =
-      React.useMutableSource || React.unstable_useMutableSource;
-
-    const mutableSource = createMutableSource({}, () => 1);
-    function Foo(props) {
-      useMutableSource(
-        mutableSource,
-        () => 'snapshot',
-        () => {},
-      );
-      React.useMemo(() => 'memo', []);
-      React.useMemo(() => 'not used', []);
-      return <div />;
-    }
-    const renderer = ReactTestRenderer.create(<Foo />);
-    const childFiber = renderer.root.findByType(Foo)._currentFiber();
-    const tree = ReactDebugTools.inspectHooksOfFiber(childFiber);
-    expect(tree).toEqual([
-      {
-        id: 0,
-        isStateEditable: false,
-        name: 'MutableSource',
-        value: 'snapshot',
-        subHooks: [],
-      },
-      {
-        id: 1,
-        isStateEditable: false,
-        name: 'Memo',
-        value: 'memo',
-        subHooks: [],
-      },
-      {
-        id: 2,
-        isStateEditable: false,
-        name: 'Memo',
-        value: 'not used',
-        subHooks: [],
-      },
-    ]);
-  });
-
   it('should support composite useSyncExternalStore hook', () => {
     const useSyncExternalStore = React.useSyncExternalStore;
     function Foo() {

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

@@ -7,7 +7,7 @@
  * @flow
  */
 
-import type {MutableSource, ReactNodeList} from 'shared/ReactTypes';
+import type {ReactNodeList} from 'shared/ReactTypes';
 import type {
   FiberRoot,
   TransitionTracingCallbacks,
@@ -47,7 +47,6 @@ export type CreateRootOptions = {
 
 export type HydrateRootOptions = {
   // Hydration options
-  hydratedSources?: Array<MutableSource<any>>,
   onHydrated?: (suspenseNode: Comment) => void,
   onDeleted?: (suspenseNode: Comment) => void,
   // Options for all roots
@@ -77,7 +76,6 @@ import {
   createHydrationContainer,
   updateContainer,
   findHostInstanceWithNoPortals,
-  registerMutableSourceForHydration,
   flushSync,
   isAlreadyRendering,
 } from 'react-reconciler/src/ReactFiberReconciler';
@@ -298,8 +296,6 @@ export function hydrateRoot(
   // For now we reuse the whole bag of options since they contain
   // the hydration callbacks.
   const hydrationCallbacks = options != null ? options : null;
-  // TODO: Delete this option
-  const mutableSources = (options != null && options.hydratedSources) || null;
 
   let isStrictMode = false;
   let concurrentUpdatesByDefaultOverride = false;
@@ -344,13 +340,6 @@ export function hydrateRoot(
   // This can't be a comment node since hydration doesn't work on comment nodes anyway.
   listenToAllSupportedEvents(container);
 
-  if (mutableSources) {
-    for (let i = 0; i < mutableSources.length; i++) {
-      const mutableSource = mutableSources[i];
-      registerMutableSourceForHydration(root, mutableSource);
-    }
-  }
-
   // $FlowFixMe[invalid-constructor] Flow no longer supports calling new on functions
   return new ReactDOMHydrationRoot(root);
 }

packages/react-reconciler/src/ReactFiberBeginWork.js

@@ -11,7 +11,6 @@ import type {
   ReactProviderType,
   ReactContext,
   ReactNodeList,
-  MutableSource,
 } from 'shared/ReactTypes';
 import type {LazyComponent as LazyComponentType} from 'react/src/ReactLazy';
 import type {Fiber, FiberRoot} from './ReactInternalTypes';
@@ -106,7 +105,6 @@ import {
   enableTransitionTracing,
   enableLegacyHidden,
   enableCPUSuspense,
-  enableUseMutableSource,
   enableFloat,
   enableHostSingletons,
   enableFormActions,
@@ -261,7 +259,6 @@ import {
   getWorkInProgressRoot,
 } from './ReactFiberWorkLoop';
 import {enqueueConcurrentRenderForLane} from './ReactFiberConcurrentUpdates';
-import {setWorkInProgressVersion} from './ReactMutableSource';
 import {pushCacheProvider, CacheContext} from './ReactFiberCacheComponent';
 import {
   createCapturedValue,
@@ -1532,19 +1529,6 @@ function updateHostRoot(
     } else {
       // The outermost shell has not hydrated yet. Start hydrating.
       enterHydrationState(workInProgress);
-      if (enableUseMutableSource) {
-        const mutableSourceEagerHydrationData =
-          root.mutableSourceEagerHydrationData;
-        if (mutableSourceEagerHydrationData != null) {
-          for (let i = 0; i < mutableSourceEagerHydrationData.length; i += 2) {
-            const mutableSource = ((mutableSourceEagerHydrationData[
-              i
-            ]: any): MutableSource<any>);
-            const version = mutableSourceEagerHydrationData[i + 1];
-            setWorkInProgressVersion(mutableSource, version);
-          }
-        }
-      }
 
       const child = mountChildFibers(
         workInProgress,

packages/react-reconciler/src/ReactFiberCompleteWork.js

@@ -41,8 +41,6 @@ import {
   diffInCommitPhase,
 } from 'shared/ReactFeatureFlags';
 
-import {resetWorkInProgressVersions as resetMutableSourceWorkInProgressVersions} from './ReactMutableSource';
-
 import {now} from './Scheduler';
 
 import {
@@ -1038,7 +1036,6 @@ function completeWork(
       popRootTransition(workInProgress, fiberRoot, renderLanes);
       popHostContainer(workInProgress);
       popTopLevelLegacyContextObject(workInProgress);
-      resetMutableSourceWorkInProgressVersions();
       if (fiberRoot.pendingContext) {
         fiberRoot.context = fiberRoot.pendingContext;
         fiberRoot.pendingContext = null;