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)

* @internal
   */
  unmountComponent: function(internalInstance, safely) {
    if (__DEV__) {
      if (internalInstance._debugID !== 0) {
        ReactInstrumentation.debugTool.onBeginReconcilerTimer(
          internalInstance._debugID,
          'unmountComponent'
        );
      }
    }
    ReactRef.detachRefs(internalInstance, internalInstance._currentElement);
    internalInstance.unmountComponent(safely);
    if (__DEV__) {
      if (internalInstance._debugID !== 0) {
        ReactInstrumentation.debugTool.onEndReconcilerTimer(
          internalInstance._debugID,
          'unmountComponent'
        );
        ReactInstrumentation.debugTool.onUnmountComponent(
          internalInstance._debugID
        );
      }
    }
  },
  /**
   * Update a component using a new element.
   *
   * @param {ReactComponent} internalInstance
   * @param {ReactElement} nextElement