RN: Inline setAndForwardRef into createAnimatedComponent.js

Summary:
Inlines `setAndForwardRef` into `createAnimatedComponent.js`.

I am planning to delete `setAndForwardRef` because it encourages a subtle bad practice with management of the referential equality of `ref` entities. I am doing this instead of refactoring `createAnimatedComponent` because this legacy implementation is planned to be replaced very soon.

Changelog:
[Internal]

Reviewed By: sammy-SC

Differential Revision: D41205066

fbshipit-source-id: dc481e73a6c4d6acbae530d4da48b3a032575179

Libraries/Animated/createAnimatedComponent.js

@@ -11,7 +11,6 @@
 'use strict';
 
 import View from '../Components/View/View';
-import setAndForwardRef from '../Utilities/setAndForwardRef';
 import {AnimatedEvent} from './AnimatedEvent';
 import * as createAnimatedComponentInjection from './createAnimatedComponentInjection';
 import NativeAnimatedHelper from './NativeAnimatedHelper';
@@ -275,4 +274,27 @@ function createAnimatedComponent<Props: {+[string]: mixed, ...}, Instance>(
   });
 }
 
+function setAndForwardRef({
+  getForwardedRef,
+  setLocalRef,
+}: $ReadOnly<{|
+  getForwardedRef: () => ?React.Ref<any>,
+  setLocalRef: (ref: React.ElementRef<any>) => mixed,
+|}>): (ref: React.ElementRef<any>) => void {
+  return function forwardRef(ref: React.ElementRef<any>) {
+    const forwardedRef = getForwardedRef();
+
+    setLocalRef(ref);
+
+    // Forward to user ref prop (if one has been specified)
+    if (typeof forwardedRef === 'function') {
+      // Handle function-based refs. String-based refs are handled as functions.
+      forwardedRef(ref);
+    } else if (typeof forwardedRef === 'object' && forwardedRef != null) {
+      // Handle createRef-based refs
+      forwardedRef.current = ref;
+    }
+  };
+}
+
 export default (createAnimatedComponent: typeof createAnimatedComponent);