Remove useMutationEffect (#31013)

https://github.com/facebook/react/pull/14336

types/react/index.d.ts

@@ -834,17 +834,6 @@ declare namespace React {
      */
     // TODO (TypeScript 3.0): <T extends unknown>
     function useRef<T>(initialValue: T|null): RefObject<T>;
-    /**
-     * The signature is identical to `useEffect`, but it fires synchronously during the same phase that
-     * React performs its DOM mutations, before sibling components have been updated. Use this to perform
-     * custom DOM mutations.
-     *
-     * Prefer the standard `useEffect` when possible to avoid blocking visual updates.
-     *
-     * @version experimental
-     * @see https://reactjs.org/docs/hooks-reference.html#usemutationeffect
-     */
-    function useMutationEffect(effect: EffectCallback, inputs?: InputIdentityList): void;
     /**
      * The signature is identical to `useEffect`, but it fires synchronously after all DOM mutations.
      * Use this to read layout from the DOM and synchronously re-render. Updates scheduled inside

types/react/test/hooks.tsx

@@ -95,11 +95,9 @@ function useEveryHook(ref: React.Ref<{ id: number }>|undefined): () => boolean {
     // $ExpectError
     React.useImperativeMethods(ref, () => ({}), [id]);
 
-    React.useMutationEffect(() => {
+    React.useLayoutEffect(() => {
         setState(1);
         setState(prevState => prevState - 1);
-    }, []);
-    React.useLayoutEffect(() => {
         didLayout.current = true;
     }, []);
     React.useEffect(() => {