I was testing latest refactor of PerfTools.
When using printOperations() often (but not always) I get 

```
Uncaught TypeError: Cannot read property 'displayName' of undefined
```

in getOperations() on the line:

```
var {displayName, ownerID} = treeSnapshot[instanceID];
```

'data-reactid="1"></div>',
          }]);
        }
      });
      it('gets recorded during an update', () => {
        var node = document.createElement('div');
        ReactDOM.render(<div />, node);
        var inst = ReactDOMComponentTree.getInstanceFromNode(node.firstChild);
        ReactNativeOperationHistoryDevtool.clearHistory();
        ReactDOM.render(<div data-x="rad" />, node);
        ReactDOM.render(<div data-x="mad" data-y={42} />, node);
        ReactDOM.render(<div data-y={43} />, node);
        assertHistoryMatches([{
          instanceID: inst._debugID,
          type: 'update attribute',
          payload: { 'data-x': 'rad' },
        }, {
          instanceID: inst._debugID,
          type: 'update attribute',
          payload: { 'data-x': 'mad' },
        }, {
          instanceID: inst._debugID,
          type: 'update attribute',
          payload: { 'data-y': 42 },
        }, {
          instanceID: inst._debugID,
          type: 'remove attribute',
          payload: 'data-x',
        }, {
          instanceID: inst._debugID,