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)

});
  it('marks top-level updates', function() {
    var ReactFeatureFlags = require('ReactFeatureFlags');
    var Foo = React.createClass({
      render: function() {
        return <Bar />;
      },
    });
    var Bar = React.createClass({
      render: function() {
        return <div />;
      },
    });
    var container = document.createElement('div');
    ReactDOM.render(<Foo />, container);
    try {
      ReactFeatureFlags.logTopLevelRenders = true;
      spyOn(console, 'time');
      spyOn(console, 'timeEnd');
      ReactDOM.render(<Foo />, container);
      expect(console.time.argsForCall.length).toBe(1);
      expect(console.time.argsForCall[0][0]).toBe('React update: Foo');
      expect(console.timeEnd.argsForCall.length).toBe(1);
      expect(console.timeEnd.argsForCall[0][0]).toBe('React update: Foo');
    } finally {
      ReactFeatureFlags.logTopLevelRenders = false;
    }
  });
  it('throws in setState if the update callback is not a function', function() {
    function Foo() {