**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

);
        serverValue = domElement.getAttribute('style');
        if (expectedStyle !== serverValue) {
          warnForPropDifference(propKey, serverValue, expectedStyle);
        }
      } else if (isCustomComponentTag) {
        
        extraAttributeNames.delete(propKey.toLowerCase());
        serverValue = DOMPropertyOperations.getValueForAttribute(
          domElement,
          propKey,
          nextProp,
        );
        if (nextProp !== serverValue) {
          warnForPropDifference(propKey, serverValue, nextProp);
        }
      } else if (
        !shouldIgnoreAttribute(propKey, propertyInfo, isCustomComponentTag) &&
        !shouldRemoveAttribute(
          propKey,
          nextProp,
          propertyInfo,
          isCustomComponentTag,
        )
      ) {
        let isMismatchDueToBadCasing = false;
        if (propertyInfo !== null) {
          
          extraAttributeNames.delete(propertyInfo.attributeName);
          serverValue = DOMPropertyOperations.getValueForProperty(