**Do you want to request a *feature* or report a *bug*?**
Bug

**What is the current behavior?**
In mobile Safari, DOM events originating from elements rendered through a Portal do **not** bubble (propagate) up the React component tree.

**If the current behavior is a bug, please provide the steps to reproduce....**
Please see the following JSFiddle: https://jsfiddle.net/zebulonj/wf7orwan/

In this JSFiddle, the expected behavior (seen in a desktop browser) is that clicking on the portal content (appearing as a modal, including backdrop) should toggle to the "On" or "Off" indicator rendered in the main content. However, in mobile Safari (iOS 11.1.1), the click events do not propagate.


**What is the expected behavior?**
Click events should propagate up the React component tree.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
Affected: React 16.2
iOS 11.1.1

/**
 * Copyright (c) 2013-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */
import {getCurrentFiberOwnerNameInDevOrNull} from 'react-reconciler/src/ReactCurrentFiber';
import {registrationNameModules} from 'events/EventPluginRegistry';
import warning from 'shared/warning';
import warningWithoutStack from 'shared/warningWithoutStack';
import * as DOMPropertyOperations from './DOMPropertyOperations';
import * as ReactDOMFiberInput from './ReactDOMFiberInput';
import * as ReactDOMFiberOption from './ReactDOMFiberOption';
import * as ReactDOMFiberSelect from './ReactDOMFiberSelect';
import * as ReactDOMFiberTextarea from './ReactDOMFiberTextarea';
import * as inputValueTracking from './inputValueTracking';
import setInnerHTML from './setInnerHTML';
import setTextContent from './setTextContent';
import {
  TOP_ERROR,
  TOP_INVALID,
  TOP_LOAD,