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];
```

type: 'update attribute',
            payload: { tabIndex: 42 },
          }, {
            instanceID: inst._debugID,
            type: 'mount',
            payload: 'DIV',
          }]);
        } else {
          assertHistoryMatches([{
            instanceID: inst._debugID,
            type: 'mount',
            payload: '<div class="rad" tabindex="42" data-reactroot="" ' +
            '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 className="rad" />, node);
        ReactDOM.render(<div className="mad" tabIndex={42} />, node);
        ReactDOM.render(<div tabIndex={43} />, node);
        assertHistoryMatches([{
          instanceID: inst._debugID,
          type: 'update attribute',
          payload: { className: 'rad' },
        }, {
          instanceID: inst._debugID,