Flow type vendor/core/merge.js

Summary:
This is used by Image.android.js and needs to be flow typed to be able to have confidence in the requireNativeComponent type change

Changelog:
[Internal] Flow type vendor/core/merge.js

Reviewed By: JoshuaGross

Differential Revision: D17561195

fbshipit-source-id: 2639f2628e15b2dd5469bb2ebfe935a444025a21

Libraries/vendor/core/merge.js

@@ -3,9 +3,12 @@
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ * @format
  */
 
-"use strict";
+'use strict';
 
 const mergeInto = require('./mergeInto');
 
@@ -16,10 +19,11 @@ const mergeInto = require('./mergeInto');
  * @param {?object} two Optional object with properties to merge from.
  * @return {object} The shallow extension of one by two.
  */
-const merge = function(one, two) {
+const merge = function<T1, T2>(one: T1, two: T2): {...T1, ...T2} {
   const result = {};
   mergeInto(result, one);
   mergeInto(result, two);
+  // $FlowFixMe mergeInto is not typed
   return result;
 };