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)

instances.forEach(function(instance) {
        instance.forceUpdate();
      });
    });
    expect(updates).toEqual([0, 1, 2, 0, 1, 2]);
  });
  it('should queue nested updates', function() {
    
    var X = React.createClass({
      getInitialState: function() {
        return {s: 0};
      },
      render: function() {
        if (this.state.s === 0) {
          return (
            <div>
              <span>0</span>
            </div>
          );
        } else {
          return <div>1</div>;
        }
      },
      go: function() {
        this.setState({s: 1});
        this.setState({s: 0});
        this.setState({s: 1});
      },
    });