Remove unused ViewportMetrics shim

scripts/rollup/shims/facebook-www/ViewportMetrics.js

@@ -1,18 +0,0 @@
-/**
- * Copyright 2013-present, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- *
- * @providesModule ViewportMetrics
- */
-
-'use strict';
-
-const {
-  __SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED,
-} = require('ReactDOM-fb');
-
-module.exports = __SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED.ViewportMetrics;

src/fb/ReactDOMFBEntry.js

@@ -40,7 +40,6 @@ ReactDOM.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED = {
   EventPluginUtils: require('EventPluginUtils'),
   EventPropagators: require('EventPropagators'),
   SyntheticUIEvent: require('SyntheticUIEvent'),
-  ViewportMetrics: require('ViewportMetrics'),
 };
 
 if (__DEV__) {

src/fb/ReactDOMFiberFBEntry.js

@@ -41,7 +41,6 @@ ReactDOMFiber.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED = {
   EventPluginUtils: require('EventPluginUtils'),
   EventPropagators: require('EventPropagators'),
   SyntheticUIEvent: require('SyntheticUIEvent'),
-  ViewportMetrics: require('ViewportMetrics'),
 };
 
 if (__DEV__) {