Run the [`fixtures/ssr` test harness](https://github.com/facebook/react/tree/master/fixtures/ssr). In the terminal, the following warning is logged:

```
Warning: Unknown prop `onClick` on <a> tag. Remove this prop from the element. For details, see https://fb.me/react-unknown-prop
  in a (at Page.js:12)
  in p (at Page.js:18)
  in div (at Page.js:17)
  in Page (at App.js:12)
  in div (at App.js:10)
  in body (at Chrome.js:17)
  in html (at Chrome.js:9)
  in Chrome (at App.js:9)
  in App (at render.js:18)
```

SSR behavior should match client-side behavior and not warn for a valid attribute.
/**
 * 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 ReactDOMUnknownPropertyHook
 */
'use strict';
var DOMProperty = require('DOMProperty');
var EventPluginRegistry = require('EventPluginRegistry');
if (__DEV__) {
  var warning = require('fbjs/lib/warning');
  var {
    ReactComponentTreeHook,
    ReactDebugCurrentFrame,
  } = require('ReactGlobalSharedState');
  var {getStackAddendumByID} = ReactComponentTreeHook;
}
function getStackAddendum(debugID) {