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

**What is the current behavior?**

Since React@16.5 seems that `root` element has `onclick` event handler with noop function.
In ios Safari/Chrome browsers html element has gray overlay when tap on it.

The current behavior is that the whole `root` is blinking when we tap on it.

The simple example to reproduce:
https://codesandbox.io/s/wyo8rlj1zk
The issue is reproducing only in fullscreen mode https://wyo8rlj1zk.codesandbox.io/
(root container is steel blue)

I suppose changes came from here:
https://github.com/facebook/react/pull/11927
https://github.com/facebook/react/pull/11927/files

and the issue can be related with:
https://github.com/mui-org/material-ui/issues/11154
https://github.com/facebook/react/issues/12717

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
React 16.5
ios 11.3/12 Safari/Chrome
if (shouldHydrate && !forceHydrate && !warnedAboutHydrateAPI) {
      warnedAboutHydrateAPI = true;
      lowPriorityWarning(
        false,
        'render(): Calling ReactDOM.render() to hydrate server-rendered markup ' +
          'will stop working in React v17. Replace the ReactDOM.render() call ' +
          'with ReactDOM.hydrate() if you want React to attach to the server HTML.',
      );
    }
  }
  
  const isConcurrent = false;
  return new ReactRoot(container, isConcurrent, shouldHydrate);
}
function legacyRenderSubtreeIntoContainer(
  parentComponent: ?React$Component<any, any>,
  children: ReactNodeList,
  container: DOMContainer,
  forceHydrate: boolean,
  callback: ?Function,
) {
  
  invariant(
    isValidContainer(container),
    'Target container is not a DOM element.',
  );
  if (__DEV__) {
    topLevelUpdateWarnings(container);
  }