Hello,

After updating to React 15.0.1, we are getting the following error:

```
Uncaught TypeError: Cannot read property 'addEventListener' of null
```

![image](https://cloud.githubusercontent.com/assets/4996164/14602577/5bb4e9f2-0571-11e6-9aa1-98de49f50d76.png)

var i;
      for (i = 0; i < desiredWillUpdates; i++) {
        expect(willUpdates).toContain(desiredWillUpdates[i]);
      }
      for (i = 0; i < desiredDidUpdates; i++) {
        expect(didUpdates).toContain(desiredDidUpdates[i]);
      }
      willUpdates = [];
      didUpdates = [];
    }
    function triggerUpdate(c) {
      c.setState({x: 1});
    }
    function testUpdates(components, desiredWillUpdates, desiredDidUpdates) {
      var i;
      ReactUpdates.batchedUpdates(function() {
        for (i = 0; i < components.length; i++) {
          triggerUpdate(components[i]);