The error event on `<source>` elements doesn't work. Looking at #4370, it seems like there is an `onError` for `<video>` but I can't tell if that's supposed to work for `<source>` too.

The error event is useful so I can deduce which format the browser is using.

});
    it('should track input values', function() {
      var container = document.createElement('div');
      var inst = ReactDOM.render(<input type="text" defaultValue="foo"/>, container);
      var tracker = inputValueTracking._getTrackerFromNode(inst);
      expect(tracker.getValue()).toEqual('foo');
    });
    it('should track textarea values', function() {
      var container = document.createElement('div');
      var inst = ReactDOM.render(<textarea defaultValue="foo"/>, container);
      var tracker = inputValueTracking._getTrackerFromNode(inst);
      expect(tracker.getValue()).toEqual('foo');
    });
    it('should execute custom event plugin listening behavior', function() {
      var SimpleEventPlugin = require('SimpleEventPlugin');
      SimpleEventPlugin.didPutListener = jest.fn();
      SimpleEventPlugin.willDeleteListener = jest.fn();
      var container = document.createElement('div');
      ReactDOM.render(
        <div onClick={() => true} />,
        container
      );
      expect(SimpleEventPlugin.didPutListener.mock.calls.length).toBe(1);
      ReactDOM.unmountComponentAtNode(container);
      expect(SimpleEventPlugin.willDeleteListener.mock.calls.length).toBe(1);
    });
    it('should handle null and missing properly with event hooks', function() {
      var SimpleEventPlugin = require('SimpleEventPlugin');
      SimpleEventPlugin.didPutListener = jest.fn();
      SimpleEventPlugin.willDeleteListener = jest.fn();