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];
```

it('gets recorded during an update', () => {
        var node = document.createElement('div');
        ReactDOM.render(<div>{'Hi.'}{42}</div>, node);
        var inst1 = ReactDOMComponentTree.getInstanceFromNode(node.firstChild.childNodes[0]);
        var inst2 = ReactDOMComponentTree.getInstanceFromNode(node.firstChild.childNodes[3]);
        ReactNativeOperationHistoryDevtool.clearHistory();
        ReactDOM.render(<div>{'Bye.'}{43}</div>, node);
        assertHistoryMatches([{
          instanceID: inst1._debugID,
          type: 'replace text',
          payload: 'Bye.',
        }, {
          instanceID: inst2._debugID,
          type: 'replace text',
          payload: '43',
        }]);
      });
      it('gets ignored if new text is equal', () => {
        var node = document.createElement('div');
        ReactDOM.render(<div>{'Hi.'}{42}</div>, node);
        ReactNativeOperationHistoryDevtool.clearHistory();
        ReactDOM.render(<div>{'Hi.'}{42}</div>, node);
        assertHistoryMatches([]);
      });
    });
  });
  describe('replace with', () => {
    it('gets recorded when composite renders to a different type', () => {
      var element;
      function Foo() {